Chapter Text
For as long as Senku could remember, he always had Tsukasa by his side.
The two first met in elementary school. Although Tsukasa was 2 years older than Senku, the older always visited Senku's classroom to hang out with him and waited for him in front of the classrooms when he started middle school.
Tsukasa didn't mind, no, he enjoyed Senku's obsession with science and protected him from others who didn't like a kid being smarter than them.
Senku was his light of hope after all.
That day when Mirai was admitted to hospital Senku declared, "There's nothing we can't fix with science. Just wait for me Tsukasa."
That was the moment Tsukasa decided that he'd do anything for Senku.
Later that week he quit school and started to fully focus on his matches. Since he wasn't 15 yet they weren't legal but it paid well enough for him to support Mirai and himself.
He was scared of Senku's reaction once he told him but all he got in return was a pinch to his cheek. "I knew you'd eventually do this. I just didn't expect it so soon." Tsukasa was stunned. "What do you mean you knew?"
Senku grinned. "You really should hide your smile as you beat up my bullies. It was no wonder you'd grow up to be a professional fighter." Tsukasa smirked. "Then you can practice hiding expressions with me so you don't watch me beating them with joy in your eyes clear as day." Senku blushed at that and pulled him by his shirt into his room and showed him a large folder full of his notes on mixed martial arts.
Tsukasa felt warm inside. Senku was preparing everything for him before he even knew. He took the smaller into a crushing hug. "Thanks." Senku now almost used to being hugged by him after many years, hugged him back. "You'll regret thanking me when I start tutoring you about all the school work you'll be skipping." He grumbled. Tsukasa smiled wider. "I knew you'd never let me off of school work."
Their high level of understanding each other helped a lot with the situation but it was still hard on Senku to see Tsukasa injured.
The first time it happened he couldn't stop trembling as he wrapped bandages around a very bruised Tsukasa. The brunet insisted that he could do it himself but Senku poked his bruise in reply. "I'm just surprised. You never got this hurt fighting off my bullies."
Tsukasa sighed. "You know this is different. No one I fight now is around my weight, height or even age range. I'll have to work hard." The despaired face Senku made at that was so heartbreaking that Tsukasa instinctively wrapped his arms around him. When he felt something wet on his shoulder he pulled him even closer. "Senku..."
The scientist pushed him away and quickly rubbed his eyes dry. "Shut up. I'll prepare you the most demonic diet plan so you better get strong fast!" He said making Tsukasa smile. "Anything you want." He replied running a hand through Senku's hair.
The days went on and they settled into a new routine. Tsukasa would drop off Senku to school in the mornings, do a little training, go to his matches or watch them if he wasn't scheduled for any and pick up Senku when his classes ended.
They'd walk home talking about their day. When they reached to the Ishigami's house or rarely, Tsukasa's house, they'd have dinner and Senku would talk to him about his new researches and experiments as Tsukasa would work out.
Senku would only tutor him on school work on weekends after they'd try out whatever experiments he had in mind. Thankfully, Byakuya didn't mind Tsukasa being around more than usual and staining few furnitures with blood. The man always made sure he felt welcomed and thanked him for taking care of his son.
//
Senku held something in his hands and quickly threw it to Tsukasa. The fighter snatched it and looked at the key in his hand. "It's so you can patch yourself up without having to wait for me." He explained. Tsukasa clutched the key. "Senku..." He smiled and added. "I'm still picking you up after school though." The white head chuckled. "You better."
It only took Tsukasa 3 days to abuse his use of the key. He barely went back to his house.
Senku's room was already his home. He had his own belongings mixed with Senku's in no time. The nightstand next to their bed had his protein supplements stacked next to Senku's small worn out notebook to write any ideas he had during the night.
Their clothes were hanged unorganized in the small wardrobe. The drawer next to the scientist's tools was filled with painkillers, creams and bandages for him. He even had a small sandbag Senku made for him in the corner of his, no, their room.
Byakuya told him that he was already a part of their family after he asked him if it was okay that he had a key to their house. It made him more than happy.
He remembered how the first few times he stayed over, Senku would grumble about having to clean up the clutter on the ground so he could sleep on a futon. Now, they didn't even mention it. His place was next to Senku on the cramped bed.
Byakuya offered to get him his own bed once but Tsukasa refused. He boldly said that he didn't want to be away from Senku. Byakuya gave him a huge smile and said he was glad Senku found a life long friend like him, although Tsukasa didn't really understand why, he seemed strangely happy.
This was the happiest he felt ever since Mirai was admitted. He had a soft smile on his face and focused on the homework Senku gave him before he heard him chuckling devilishly looking at his computer. "What are you up to now?" He asked from his place on the ground.
Senku turned to him with a huge smile. "I finally got an answer to my mails! And from a Nasa scientist!" Tsukasa felt excited for his friend. "Really?! Show me too." He walked over and looked at the screen. "Oh...It's in English." He said, dissapoined.
"Heh. I'm already studying it. I can't wait to try out his suggestions!" He said and immediately got to work as he explained to him what Dr.X suggested him. Tsukasa listened and hummed along. Seeing Senku so excited and happy made him feel warm. But there was part of him not really liking the situation. He buried those thoughts deep. He didn't want to ruin Senku's happiness with his useless comments.
When Senku was ready to test his small rocket, it was already night time but being so excited, he couldn't wait until the morning so they walked to the closest riverbank. Senku's hands were empty except for a notebook and a pen. Tsukasa, as usual, was carrying everything.
When it failed to take off properly, Senku smiled and wrote down his observations, not deterred at all. Tsukasa already knew how important failure was from being around the scientist so he silently watched to not interrupt Senku collecting pieces.
After a few more tries Senku started to yawn and Tsukasa hauled him back inside despite his protests. "Come on! At least let me mail my findings to Dr.X, it should be morning in America. He won't reply as fast if I wait until morning." He whined.
Tsukasa sighed. "Fine. But don't think of getting used to staying up late so it's more convenient for Dr.X." Senku grinned and rushed to type his thoughts as Tsukasa changed into comfortable clothes and laid on the bed. When Senku finally climbed over him to squeeze between him and the wall, Tsukasa was finally comfortable enough to fall asleep.
The next day he woke up earlier than usual because Senku was trying to slip away from his arms. He automatically tightened up. "It's 6 am." He stated after glancing the clock.
Senku glanced at him annoyed. "So what?" Tsukasa didn't reply and stared at him until Senku turned away with a blush on his face. "I wanna see if Dr.X replied." The brunet hummed and allowed Senku to slip out. "Fine. Not like you'd be able to go back to sleep with how excited you are." He said. Senku immediately rubbed the sleep away from his eyes and checked his computer. He brightened up seeing the response.
Tsukasa watched him typing away and taking notes. He too decided to have an early start and went ahead to take a shower.
When he got out Senku was still in the same spot, "You're still talking with him?" He asked. Senku seemed to absorbed in his chat with the scientist to hear his question. Tsukasa felt irritated enough to leave him alone and prepare breakfast.
When Senku finally got up, he was too busy reading a thesis Dr. Xeno wrote and kept reading it as Tsukasa took him to school.
The older knew how Senku got when he was interested in a something or even rarely, someone so he kept quiet. His excitement about his new mentor would pass in a few days. Or so he thought.
By the day 3 of Senku either ignoring him or talking about Xeno's achievements and thesis, he was fed up.
What bothered him wasn't that he thought Xeno was evil or anything, no he was happy Senku had someone to inquire about everything he thought. Just that it was the first time Senku was so deeply interested in someone other than him.
He hated how Senku seemed to enjoy talking to Xeno more than him and it was making him go crazy. He never felt that their friendship might not be as secure as he thought until now. Jealousy was eating his heart.
Was Senku getting bored of him? The thought made his head go blank. No. He wouldn't allow that to happen. He'd gain back Senku's attention one way or another.
Good thing he had a match today.
Notes:
First chapter is done! I know I kinda skipped over some parts but I'll compensate it with my other already written out chapters I didn't wanna drag it out from the start and get to what I actually wanna write faster ahaha
Chapter 2
Notes:
I couldn't wait 😭 I can't hold myself back from updating especially since the first chapter is so damn short and nothing much even happens in it so here is chapter 2! I hope everyone enjoys it!
(See the end of the chapter for more notes.)
Chapter Text
Senku was waiting in front of the school by himself. It was unusual as his best friend was almost always ready to walk back home with him. He sighed and opened his phone to keep reading an article Xeno recommended him. He'd scold Tsukasa when he came.
5 minutes later when Tsukasa finally arrived, Senku didn't even lift his gaze, he recognized Tsukasa from his shadow and started talking. "What are you so late for? Did you know it's been-" He then looked up to see his best friend covered in bruises. Black eye and all that. He looked almost bad as the first few times he fought. "Ah. Sorry Senku." He replied and held his side with a wince. "Today was a bit hard." Senku's face went slack in horror.
He quickly dropped his phone into his bag and pulled Tsukasa gently to get him to walk. They walked home in silence with quick steps and not once did Senku let go of him. Tsukasa smiled. If this was the price he had to pay, then so be it.
Senku immediately closed the door of their room behind them and rushed to bring out medical supplies. He asked the fighter to take off his shirt and pants so he could see the full damage.
He gasped at the sight. Tsukasa had a huge bruise on his right side and a shallow cut, probably made with a fingernail, going along his leg. His back almost fully was purple. "How did this even happen?" He asked, frustrated.
"He was strong." Tsukasa replied calmly. Senku's red eyes turned angry. "How are you so calm? There's no way you can fight tomorrow like this!" He knew how Tsukasa hated having to sit out on matches because he had to heal. When he got no reply, he pushed a painkiller and a glass of water to the brunet.
Tsukasa didn't even look at the glass.
Senku huffed loudly. "Come on, what's wrong with you? Take the medicine."
The brunet's eyes turned cold. "No."
"Hah? What do you mean no? Just take it. There's no way it doesn't hurt." Senku said panicking more every second.
Tsukasa turned his head away and looked out of the window.
Senku clenched his teeth and took Tsukasa's hand to force the glass of water onto him. When Tsukasa refused once again he slammed it on the ground, making it spill. "Fine. What do you want then? Speak already!" He demanded.
At the same time a notification sound from his computer came. Tsukasa gritted his teeth. "Go check that first." He said bitterly, still not meeting the scientist's gaze.
Senku's mouth dropped open. This was his problem? He was...jealous? The younger stood up quickly and pulled Tsukasa's arm with him, urging him to follow.
He complied and they stood before his computer. Senku sat down started to type as his best friend watched with his arms crossed.
He started to read out loud as he typed, "Sorry Dr.X but Tsukasa, my best friend that I mentioned before is much more important. I'll get back to you when I'm available." He pressed send and looked at Tsukasa. "Are you satisfied now." He asked still angry.
Tsukasa's gaze softened a little but he stood stiff. "What? Don't act like I forced you to do that." He said. Senku realized he misunderstood and walked closer to him and pulled the long brown hair down gently so they were looking right into each others eyes.
"I'm angry because you got yourself beaten up on purpose dumbass. Compared to you I don't care about Xeno or anyone else 1 millimeter. Just tell me outright next time you have something bothering you. I did get a bit too excited having new materials to study but that doesn't chance anything."
Tsukasa's eyes widened and he hugged Senku. "I'm sorry." He said despite not regretting a single thing. He repeated Senku's words in his head and smiled.
The scientist must've known his feelings from his tone. "You know you're crazy right?"
Tsukasa resisted the urge to lift Senku up to hug him properly. "I'm your crazy." He said making Senku chuckle. "Good. Now let me fix you okay?" Tsukasa let him go and finally took the painkiller as Senku wrapped him in bandages. "Promise me you won't get deliberately hurt again?" The white head asked holding his pinky up. Tsukasa smiled and wrapped his pinky around his. "I promise."
After this incident Senku made sure Tsukasa was getting enough attention even when he was talking about Xeno. Making sure to include him in the pictures of the experiments he took to send it to his mentor. Tsukasa was happy, feeling his place next to Senku was cemented but now that Senku told him to just say his worries outright, he started to voice his wants more clearly.
It started out as him asking if he could read their mails. He was curious after Senku told him he already mentioned him to Xeno.
His best friend didn't object and allowed him to read everything. Soon enough, it wasn't just about wanting to read parts about him but all of their talks even though he wouldn't be understanding the advanced scientific things they talked, he asked Senku again.
This time he was outright given the password to his computer and told to look at whatever he wanted whenever.
Tsukasa was surprised at how easily Senku allowed him into his boundaries. "You really don't mind?" He asked curious.
"Why would I be? It's not like there's anything you don't know about me. Did you forget we sleep together every night Lion?" He laughed. Tsukasa grinned and relaxed his stance. "Right. What was I thinking." He said with a gentle smile.
Over the time Tsukasa grew more relaxed about Senku growing closer to Xeno but when Senku nervously asked him if he'd mind them having a video call, Tsukasa couldn't help glaring Senku for a second before managing to calm down. "...Sure. You wouldn't mind if I watched right." He asked without actually asking.
Senku nodded and sat down getting ready to call Xeno as Tsukasa stood behind him with a hand on his shoulder, looking like he was about to get on the ring.
Senku couldn't help but to be happy in a way. Tsukasa was always there for him, ready to protect him. Talking with his mentor was making him a little nervous too but the heavy hand on his shoulder calmed him.
Xeno picked up almost immediately and greeted them. "Hello Dr.Senku and Tsukasa Shishio." He ignored the way Tsukasa glared at him through the screen. Senku returned his greeting.
"Hey Dr.X you don't mind if he stays right?" He said pointing to the brunet behind him. Xeno gave him a knowing smile. "Of course not. I've told you about Stan right? Our situations seem similar so please don't worry about my opinion. Now, let me hear your observations on Ebola."
Senku nodded and the two immediately launched into a discussion about it. Only 2 hours later when they finally ended the call could Tsukasa relax. He stretched and ran a hand through Senku's hair before disappearing into the kitchen to bring the younger a glass of water.
Senku took it and quickly drank it. "Thanks. My throat was hurting."
"I know. Let me know when you call him again?" He asked. Senku hummed. "Sure. Just know that you're being reallyyy annoying okay?" Tsukasa laughed. "Yeah? Since when did you start lying? Just accept you like it too." Senku grumbled and turned back to his notes as he handed him the empty glass.
Tsukasa smiled. He's known that Senku actually liked when he got jealous and controlling for a while. It was back in elementary school when Tsukasa first noticed it.
He'd end up interrupting and dragging Senku away while he was talking to his classmates when he got fed up. He was surprised at Senku not being angry about it but instead acting like nothing happened. Tsukasa had been trying to control more of his jealousy ever since then, anxious that Senku might hate him if he always did as he pleased. Only now he could test the waters freely and he trusted Senku to tell him if he got too much.
He knew Senku was just embarrassed to admit. Tsukasa felt annoyed that his best friend could get embarrassed from him. He made it clear many times he'd accept anything Senku threw at him.
He'd have to make sure he couldn't deny it then. He smirked and thought of all the things he had to stop himself from doing.
It was unsurprisingly a lot. It took him a while to decide but he made his decision and returned to Senku's room.
"Hey Senku. Let me cut your nails." He said with a calm smile on his face.
"Ha? Where did that come from?" Senku questioned looking at him with a brow rised. Tsukasa shrugged. "Can I?" he asked again not explaining anything.
Senku took another moment to look at him weirdly and responded. "...Okay." Tsukasa smiled and opened their bedside drawer to pick up the nail clipper and motioned Senku to sit on the floor. He opened a palm and watched as the small hand was placed in it. He carefully shortened the already short nails. When he was done with his hands Senku tried to sit up only to be pulled back down by him. "Where are you going so fast?" He said.
Senku understood what he wanted and muttered, "You really lost your mind huh?" He placed his foot on Tsukasa's lap and averted his eyes from him.
He took a big sigh when it was over and turned to his notes quickly, not minding Tsukasa cleaning up with a satisfied smile behind his back.
Another surprise came when Tsukasa walked into the bathroom and watched him brush his teeth. He looked at him through the mirror but only got that innocent looking smile that definitely meant he'd do something weird again. He rinsed his mouth and turned to him. "What now?"
"Open your mouth." Tsukasa demanded.
"I swear if you put a bug in my mouth-" He complained early on but still opened his mouth. Tsukasa laughed. "When did I ever shove a bug in your mouth to make you think that?" He chuckled and pried Senku's mouth to open more with his fingers as he looked at the white teeth carefully under the bright lights of the bathroom. He ignored the questioning noises Senku made and checked the few he couldn't quite see with his fingers.
When he pulled away he ignored the look Senku gave him and washed his hands. "So? What does my dentist think?" the scientist asked with an amused voice.
Tsukasa hummed. "Not bad. They look clean." Senku huffed. "Not gonna tell me what's all this about?" When Tsukasa ignored him he gave up and laid down on their bed thinking he must be doing weird things because he probably didn't like him talking to Xeno.
The next day was going relatively normal until he approached to Tsukasa who was waiting outside his school to walk back with him. The moment he got close enough a hand wrapped around his nape.
"What are you doing?" He asked.
Tsukasa hummed. "Doing what?" He said and pulled him closer as they walked.
Senku once again gave up and asked about how his match went instead.
When the night came Senku was rushing through his school homework when Tsukasa one again demanded his attention.
"Here, have some." The fighter said and extended him his hand, holding a small piece of beef jerky. Senku didn't mind an occasional snack so he reached out only for Tsukasa to pull it back. "Open your mouth." Tsukasa instructed him, patiently waiting for him to comply.
Senku took a moment to consider if he'd prefer getting his fingers dirty which where on his papers or get hand fed by his best friend. He opened his mouth with a mocking ahh sound making Tsukasa chuckle. "Be grateful a little. I'm feeding you here you know?" The brunet replied and fed him pieces after pieces as Senku kept doing his homework.
Senku turned up to him when his homework was over with a hum. "I actually like this. It's efficient to eat without getting my hands dirty."
Tsukasa smirked. "I know you like it. You know you can tell me anything right?" He added on. "Obviously dummy. You're the only one I tell everything." Senku said with a slight smile. He'd usually take a more mocking tone but he preferred to reassure any doubts Tsukasa had.
The night came and only when they were wrapped in each others arms on the bed did Tsukasa ask. "Do you like it?"
Senku didn't seem surprised at his question. He took a moment to think. "I do. There's no one but you and Byakuya that cares about me enough to want to take care of me, so do whatever you want to." He said as he looked into Tsukasa's brown eyes under the moonlight.
Tsukasa didn't seem fully convinced. "You know it isn't normal for me to try to control everything about you right?" Senku pinched his cheek. "Obviously I do. I could never trust anyone else to do so and just so you know, I did my research on it." Tsukasa laughed and held him tighter. "Of course you did. Nerd." That earned him a kick from the scientist. He couldn't help but to tease him further. "Were you trying to tickle me or what?"
Senku groaned. "Shut up gorilla. Sleep already." Tsukasa obeyed and pressed a kiss on his friend's forehead.
The next days passed on with their new normal and few more additions. The more Senku allowed Tsukasa to do as he liked, the more his wants grew and knowing that Senku enjoyed it as much as he did didn't help.
He found that, he would very much like to take showers with Senku. This wasn't absurd of course, his best friend must've realized that he wanted to help him with these tasks like they used to do so when they were younger. The problem was that Tsukasa was getting annoyed at the bathroom door.
Yes, he was getting annoyed at a door. Anything separating him from Senku was annoying and much less a locked door. He wanted to be able to just walk in and wash Senku's hair. It was Senku's fault for just telling him to stop asking everytime he wanted to feed him or check his teeth and nails, otherwise he wouldn't ever let himself get so ahead with these ridiculous wants.
But surly, Senku would understand or at least offer something to appease him right? So one day after school when Byakuya was busy, he sat them down and said it. "Senku. I don't like it when you lock doors."
Senku lifted a brow. "I don't lock my room door anyways?" Tsukasa kept looking into the crimson eyes hoping for him to understand his desire somehow. Of course, his best friend soon realized it and made a face. "Wait...Are you seriously asking me to keep the bathroom door open as I pee?" He asked bewildered.
"Well...I wouldn't mind that too but no, I'm asking you to not lock it when you're taking a bath." Tsukasa explained. Senku's expression relaxed a little. "You crazy lion. I don't want Byakuya walking in on me showering or worse, us showering together."
Tsukasa hummed. "Yeah. That'd be hard to explain...But still..." He trailed off not wanting to give up. Senku sighed. "I guess I can teach you how to lock pick if that'd help." Tsukasa brightened and smiled as he reached a new conclusion and hummed "So you like it more when I just do it instead of asking you." Senku blushed realizing that he could've offered to talk beforehand when Tsukasa would join him so he could leave the lock open instead of lock picking.
He thought more about what exactly he liked about it and answered Tsukasa. "I guess I want you to decide when to join me or not. It just...sounds better that way?" He tried to explain his feelings.
Tsukasa's heart skipped a beat at that. He ran a hand through the white hair and hummed. "Good job for telling me." He said making Senku melt.
What followed next was a quick lesson about picking locks with common household objects as Senku obviously didn't have the professional tools for it. Turns out most bathroom doors are made easily open from outside in case of an emergency so it was quite easy to do so.
Satisfied with his newly gained skill, Tsukasa decided to test it out quickly. He waited until night the next day to hear Senku turning on the shower. He didn't waste anytime and opened the lock.
Seeing Senku with his hair down looking at him with a small smile made him happy. He quickly stripped and stood behind Senku as he started to massage the smallers scalp.
Senku made noises that showed how much he enjoyed a massage and leaned back into his chest with all his weight. Seeing Senku so relaxed and vulnerable in a way was so great that Tsukasa regretted not doing it sooner. He wrapped an arm around Senku's waist to let him relax fully as his other hand worked the shampoo into his hair.
After they were done the brunet dried Senku's hair and felt more relaxed than ever.
Notes:
Ngl I just love 'The shape of us' (a bl manhwa) so much I had to add the little part of it I love although the uke of the manhwa doesn't like being micro managed I do love reading about it so that's where the nail cutting and teeth checks came from lol (it's awkward as hell when I actually have to write it out but damn it I enjoy those small obsessive acts too much)
Things are gonna get explicit at the next chapter! Ofc with lots of fluff and feelings involved I'll see yall soon!! 💕
Chapter Text
Another difference in their lives came when Byakuya finally achieved his dream of becoming an astronaut. Saying goodbye to him was harder on Senku than he ever let it show.
Tsukasa was also sad that he would be losing the only reliable adult in his life but mostly he was happy that he could chase his dreams into the space. Ah, also that he and Senku would be alone. Not that it would chance much, just living alone with Senku felt more intimate in a way.
For Senku however, being alone with Tsukasa was going to be a little more different.
He's been always aware that his body was growing, it was proven further when he started to grow white, barely visible hair along his body. Maybe in another universe he wouldn't have cared one bit about it but he was undoubtedly excited to become a teenager now. All because of Tsukasa of course.
Tsukasa was 2 years older than him which meant his changes started much earlier and Senku was very aware of them. His best friend was getting taller as days went on and showed no sign of stopping. His body was growing much more muscular even when he hadn't changed his training and most obviously, his boners that appeared around him.
Although they haven't talked about it Senku was sure about one thing. He and Tsukasa were dating.
Anyone with eyes could see, they were closer than any other friendships Senku had seen. He couldn't imagine him or Tsukasa finding someone else to date no, he was sure his best friend who wouldn't even like it when he made other friends would accept him dating someone. It was the same for Senku. He simply couldn't picture anyone esle intruding on him amd Tsukasa.
Their relationship was always that of a lovers now proven further by the obvious sexual attraction Tsukasa had for him.
Tsukasa being a good person, had ignored it everytime it happened. Of course he would, it would be weird to when he hadn't even entered puberty yet. So in Senku's mind they were waiting until his body matured to finally start looking at the sexual nature of their relationship.
They had been doing the romantic, emotional part of it since forever, as he talked about it with Xeno who also agreed with him. His mentor wasn't surprised a least bit when their usually science based conversation turned into something more personal, in fact he also talked about how his relationship with his husband, Stanley Snyder, started so they could have more data about the situation.
They both reached the same conclusion as always of course. They were clearly already dating and there was very little chance Tsukasa didn't think the same considering his always accurate and fast way of understanding Senku, sometimes faster than he himself did.
The more they talked the more information Senku got. Xeno was very helpful when it came to letting him know how sex was between males. He instructed him that most things he'd see on internet would be misleading and that he could ask him any questions he had. Xeno admitted that helping him through any obstacle in his life no matter the subject would make him more than happy as his mentor.
Senku was glad as the only other person he could ask would be Byakuya otherwise. Xeno was a good confidant. He was experienced and shameless enough to explain his underage mentee how to do sex prep step by step.
//
The expected moment came, quite literally, when he was sleeping in Tsukasa's arms. One moment he was asleep the other he was frantically rubbing himself on Tsukasa's leg with barely muffled moans.
He only realized what was happening when he came shortly, ruining his underwear. He heard a gasp above and tilted his head to see Tsukasa clenching his teeth with clearly dilated eyes. "Senku. You- you should clean up." He stammered out trying to hide how affected he was, as if Senku couldn't feel his boner against his wet sleep shorts. Senku hummed and rubbed his eyes trying to properly wake up. "In a rush to get me leave?" He asked.
When Tsukasa didn't answer Senku chuckled lightly. "I don't mind helping you out." He added. The brunet took a sharp breath at his words. "Don't joke around and do as I say." He said.
Senku was surprised at the order, maybe Tsukasa wasn't ready? Well, whatever he got defensive about could be solved later. He jumped over Tsukasa and grabbed a new set of clothes before going into the bathroom, leaving Tsukasa alone.
When he came back and squeezed back into his place between Tsukasa and the wall, he started to talk. "Want to explain what that was?" He asked approaching the subject in a loose matter.
Tsukasa placed a hand over his eyes. "I'm sorry Senku. I'm sure you already know it's just a biological reaction."
Senku raised a brow. "What are you apologizing for?" He asked.
"For getting hard because of you." Tsukasa said in a upset voice. Senku immediately raised from where he was laying with a huge "Hahhh?!?" Leaving his mouth. Surprised by the extreme reaction, Tsukasa also looked shocked.
"Tsukasa. I'd be offended if you didn't get hard for me and what are you being so shy for? It's not like this is the first time it happened." He said.
Tsukasa averted his gaze. "I wasn't sure you realized." Then Senku's words registered and he looked at him. "What do you mean you'd be offended?" He asked.
Senku huffed and crossed his arms. Seems like they weren't on the same page at all. "Tsukasa. We're dating. Of course I'd be offended if my lover couldn't get it up for me."
Tsukasa in his shock gripped Senku's shoulders. "What?? Since when?" He asked. "I don't know, since forever. I didn't think you wouldn't realize it on your own." Senku replied calmly with a shrug.
It took Tsukasa for a moment to think of all the things they did that were far beyond the boundaries of friendship and quickly reached the same conclusion. "We are dating..." He mumbled. Senku smiled. "Yes, we are." He said and touched their foreheads together before adding. "I love you Tsukasa. I have, for a long time."
Tsukasa couldn't look away from the ruby eyes and he quickly gave his lover a peck on his lips. "I love you too Senku. More than anything." He said and kept giving him soft kisses all over his face.
Senku tangled his fingers in Tsukasa's long hair, encouraging him for more. However his boyfriend stopped at that. Senku made a questioning noise.
"I would love to keep going, trust me I would, but don't you think we're taking it too fast? I'm sure you'd prefer to know more about your body before we take things further." The fighter said.
"I've been waiting for this a long time you know? But you're right. I'd prefer experimenting myself for some time." He said and patted Tsukasa's head. "You know me so well." He praised him.
Tsukasa's took his other hand to kiss his palm. "Of course I do. You're all I look at."
They tried to settle back and get some sleep for the night but it was obvious they couldn't as they both could feel each other's heartbeat going crazy. Tsukasa sighed and stood up, pulling Senku into a princess carry as he did. He didn't mind his boyfriend's surprised gasp and carried him to the living room.
He placed Senku carefully on the soft couch and took the remote before placing Senku into his lap. He opened a channel that Senku liked watching, about how various things are made, and placed his chin on top of Senku's head.
They ended up dozing off on the couch feeling more comfortable than ever.
Notes:
They're a couple now! A fast burn as I promised ahaha I know this chapter is once again really short but the next one will almost be everything I've written till now (with smut starting for real too) I actually didn't cut this into chapters at all when writing so now that I have to, it feels awkward and hard to decide where cut it from lol
I hope everyone enjoyed!!💕
Chapter 4
Notes:
Finally a long chapter!!! With lots of smut too and obviously a little kinky! It's my first time writing it so have mercy lol
(See the end of the chapter for more notes.)
Chapter Text
The first person they told about their relationship was Mirai. They visited her right after the school ended the next day. The hospital and Mirai was same as ever, Tsukasa made sure to visit her every week sometimes bringing along Senku. This time however, he was feeling happy.
"I love him so much, I can't believe he's mine. I never imagined my life being so happy and normal like this. I thought it would be over when you were comatosed but here I am. You'll have a bigger family when you wake up, Mirai." He said with a smile.
Senku could feel himself tear up at the heartfelt words. For Tsukasa to say such things to Mirai, someone who he could never lie to... He must truly love him. Not that he had any doubts but seeing it laid bare made made him elated.
The next person they told was Xeno. Senku thought about calling Byakuya to break the news but he wanted to see his surprised face when he learned. A phone call wouldn't be as entertaining.
They once again planned a video chat with the American and surprisingly Tsukasa didn't mind as much as he was busy doing handstand push ups behind him.
Xeno picked up his call and started to talk. "Hello Senku. I hope you're doing well." He said and took a moment to quickly understand the situation. "Ah, congratulations Senku. I see you two are finally dating."
Senku chuckled. "What gave it away?"
Xeno hummed. "He was hovering over you with a hand gripping your shoulder the first time. He must have a reason to be on less guard now he doesn't feel the need to completely give you all his attention. A reassurance of you two's relationship must've occurred."
"Ten billion percent correct. Although I'd say he did get more relaxed before hand when I told him you were happily married." Senku added. Tsukasa stood back up right and walked closer adding his own information. "I hope you don't mind me listening in. I was on guard due to your young age as I imagined someone in their forties when Senku told me about you."
Xeno nodded. "You were worried that my intentions with Senku might not just be mentorship. Of course, I understand. My husband and you seem to be very similar in that aspect, me and Senku have nothing to hide so listen as you'd like."
Tsukasa nodded and went back to exercising as Senku changed the topic into another failed experiment of his and asked him what new equipment he should get with Byakuya's card.
//
Ever since the day Senku started to date Tsukasa, he's been given back his 'freedom' of showering alone. They didn't need to talk about to know that this would be Senku's self exploration time.
He unexpectedly got embarrassed at the thought of buying lube so he ended up making one himself to try out. He quickly got used to jerking himself off. Just the thought of Tsukasa was enough to get him hard most of the time. He liked to imagine Tsukasa walking in on him or remembered his lips against his.
Next, he tried feeling some common erogenous zones along his body. He was quick to discover his ears, neck and nipples were sensitive. He wanted feel Tsukasa's huge hands running along his body already but he still wanted to try something else.
He knew it wasn't necessary or anything, Xeno made sure to educate him properly, that sex didn't mean penetraion and that he would be uncomfortable before getting used to it but he still wanted to test the waters.
He coated his hand in oil and placed a finger around his rim. The texture was weird but he paid no mind and tried poking in with his his index finger slowly. The intrusion was a weird feeling. He slowly pushed in until he was almost up to his first knuckle before stopping and giving himself some time to get used to the feeling. He breathed out and pushed more. he repeated the motion until his whole finger was in. The feeling of his insides weren't much to note, it just felt slippery and warm. A little disgusting too if he had to admit.
As he assumed it wouldn't be enjoyable unless he managed to find his prostate. He doubted his small finger could reach it but he tired probing around for it before giving up and deciding to add another finger in.
He eventually worked himself open enough to add the third finger before deciding he had enough practice. It was the time to try something new.
He washed his hands thoroughly and wrapped a towel around his waist which didn't do much to cover the small bump his hardness made. He walked into the living room to see Tsukasa watching a MMA match on TV.
He quickly made his way to his boyfriend and sat on his lap as he wrapped his arms around his neck. Tsukasa's hands immediately wrapped themselves around his waist. The moment he opened his mouth to probably ask what he was doing Senku placed his tongue in. Tsukasa didn't waste any moment and sucked on it as his hands tightened around him.
Senku pulled away for a moment. "I was thinking it's about the time we try something new." He said and rolled his hips forward.
Tsukasa hummed and smiled. "About the time." He undid the towel around him and took his time observing him before finally touching him softly. At Senku's unintentional urge to squeeze his legs he placed a hand in his inner thigh to keep him separated.
Senku couldn't help but to make noises everytime Tsukasa ran his hand through his body. The hand on his inner thigh tightening only made it better. "T-Tsukasaa make me come already!" He whined.
The brunet's eyes were dilated and his dick looked like it was about to burst from his pants but he sounded almost calm and collected, "Hmm, I'm sure you can think of a better way to ask." He said pulled away his hand to roam his body.
Senku pulled at his hair. "Please, please make me cum?" He asked not being able to take the feather light touches. Tsukasa smiled at him. "Good." he said and probably started to jerk him off.
Embarrassingly Senku didn't last much and came all over Tsukasa's hand. His eyes widened seeing the man licking it off his hands, tasting him.
Unable to resist the curiosity he pulled Tsukasa's hand to himself and licked a long stripe on his hand. It was salty.
He heard Tsukasa's breath hitch before he quickly undid his pants and brought Senku's hand on his throbbing dick.
The scientist looked at it in wonder, touching it directly was much more different than just feeling it against his back. It was so thick and warm he could barely wrap a hand around, he could tell Tsukasa was really about to burst. He felt good seeing that he was as affected by he himself was.
He didn't waste anymore time and tried to copy what Tsukasa did to him, repeating anything that the other moaned at and soon enough his hands were covered in a thick layer of cum.
Once again, curiously, he licked his hand clean. It didn't taste much different but just knowing it was Tsukasa's made him enjoy it beyond the taste.
The huge hands were back at grabbing his waist as he went on. Senku chuckled. "You'll leave handprints." He stated still feeling out of breath. Tsukasa bit his shoulder in response. "I want to mark you."
Senku shuddered and layed his head on Tsukasa's shoulder. He would love to bite him back but knowing he went on the matches shirtless, he restrained himself and gave him kisses instead.
He was still a bit spent when he felt Tsukasa's hardness poking his stomach and hands grabbing his ass. He yelped and pulled away quickly.
Tsukasa looked at him with guilt, "I know it's too soon for that but... You look so perfect Senku. I could eat you up." He said and licked his lips.
Senku blushed. "If you like groping my butt go ahead. It's not like anyone else is going to see your handprints there."
Tsukasa tightened his hands further at his words and leaned on his chest to bite around his nipple making Senku moan.
"No one is going to see this too so it's okay right?" He asked playfully and licked his hardening nipple.
Senku couldn't answer due to how amazing it felt to be touched and licked by Tsukasa. Nothing he did by himself could compare to being touched by the person he loved.
Not wanting to leave his boyfriend unattended, he reached down and wrapped his hands around both their dicks. "Let's come together hm?" Tsukasa eagerly thrusted up into his hands and soon they were coming as Tsukasa stopped playing with his chest and pulled him into a messy kiss.
When Senku felt the brunet once again stirring to life he pulled away from his arms. Tsukasa pouted at him. "Are you too tired for another?"
Senku huffed. "You really don't need any recovery time do you? Crazy lion." He stood up and wiped his hands on his towel before passing it to Tsukasa. "We could take a shower together." He added making Tsukasa smile brightly.
Needles to say, they did keep going for a while.
It took Senku a week to finally gather up courage and tell Tsukasa that he was fully ready. He was sure if he once again just walked up to him and demanded they try penetration, his lover wouldn't mind it at all but this felt more serious in a sense that he should ask him properly. It wasn't just about him after all.
He washed himself thoroughly and prepared himself well enough to wash his insides instead of fully stretching himself, he wanted Tsukasa to do that.
He dried his body fully and grabbed the hair dryer to hand it to his lover who was already sitting on his bed waiting to dry his hair for him.
The familiar motion of Tsukasa taking care of his hair calmed him and once the dryer was off he placed a hand on Tsukasa's leg.
"I was wondering if you were ready for taking things further?" He said quickly, not turning around to meet his eyes.
Enjoying how shy Senku got Tsukasa teased him. "Further? Like what?" He played dumb. He could see the redness on his lovers ears.
"You know... Like penetration."
Tsukasa held in his laugh and hummed. "You want my fingers in your mouth?"
Senku finally turned around with a red face looking at him. "You're doing it on purpose!"
Tsukasa let out his laughter and patted his head. "I can't help it, you rarely get so shy. So tell me what you want in detail hm?"
Senku crossed his arms but complied. "I want you to finger me and then fuck me. There. I said it." He said trying his best to not break eye contact. Tsukasa leaned in closer and gave him a short kiss. "You did well. I would love to do everything you want me to do." He said not missing how getting praised seemed to make Senku's blush deepen.
Tsukasa wrapped his arms around the scientist and pulled him up on his lap. "Senku. Are you sure you're ready? I don't want to rush anything between us, I'd wait for you forever." He asked wanting to make sure the shyness, as cute as it was, wasn't a sign of doubt.
Senku wrapped his arms on his neck and gave him a peck. "I am sure. I want all of you Tsukasa."
Tsukasa smiled and kisses him back while pushing him down to the bed. He slowly stripped Senku out of his loose clothes all while kissing him until he was completely naked underneath him. He took a moment to look at his lover, he was gorgeous.
The small body was full of his hand prints and marks, he was quick to realize Senku loved them after he caught him checking them in the mirror with a certain look in his ruby eyes. Ever since then he made sure his pale body was never left unmarked.
He leaned down and trailed kisses along his chest before continuing down to his legs before Senku pulled his hair lightly to get his attention.
"Won't you get undressed too?" Senku asked looking embarrassed enough to cover his face with his arm. Tsukasa leaned into his ear to whisper. "Is it embarrassing being the only one naked?" Senku twitched and nodded.
Tsukasa pulled his arm away from his face and started to strip, fully aware of how Senku's eye watched his body moving with great interest.
He pulled off his underwear and sweatpants in one go before allowing Senku to push him down and touch all over his body.
The small hands mapped his chest out dipping and pressing every curve he had making it really hard to just stay still and let Senku explore him without trying to lift his hips to get some relief.
The hands went further down along with pink lips on his body, leaving small kisses on his weeping cock but continuing down to his legs instead of focusing on it. Tsukasa ended up placing a hand on the spikey hair of his lover. "You check my body like it's the first time you've seen it." He said.
Senku smirked at him. "You mean just like how you did?" he said before blushing and adding, "You know it's much more different when I know we're about to do it." Tsukasa also blushed at the honest explanation and sighed playfully. "I'll let you do as you like then."
Senku hummed in response and turned his attention back to his calves with a hungry look in his eyes. Tsukasa loved how much Senku appreciated his hard earned muscles and waited until his lover sat on his lap and handed him a jar of homemade lube.
Making sure to coat his hand properly he eased his finger in only to stop when Senku made a pained sound. "Did I hurt-" he started.
"No! no, just keep going. It feels good." Senku interrupted him. Tsukasa was watching his reactions more carefully than usual, noting that the pained sounds were usually accompanied by a twitch of his dick. He had to stop himself from coming at the sight, how Senku seemd to love everything as long as it was him who gave it made him feel elated.
He could do anything he wanted and Senku would allow him to. The thought made him unable to resist the urge to bite deeply into his lovers shoulder as he slipped in another finger. The loud moan in response was music to his ears.
He kept going like that until he managed to fit in a third finger When Senku stopped him to say, "It's enough. Put it in Tsukasa."
"I will. Just let me get-" He started about to pull away from Senku to take out the condoms he bought when he was interrupted with a small hand holding his shoulder.
"No, Don't. I want to feel it fully. It's not like we have any STD's." Tsukasa laughed. "Hm. True, we're virgins. Don't worry I'll make sure you can't feel anything but me soon."
He pinned Senku on the bed and placed himself between the thin legs, throwing one on his shoulder exposing him completely. He could see the ruby eyes looking at his dick with slight worry and a much more obvious excitement.
Tsukasa slowly put in his tip making Senku moan. "Are you scared it'll hurt?" He asked trying to hold back from fully entering the tight insides. Senku's feet on his shoulder kicked into him, "I don't care if it hurts." he replied.
Tsukasa pushed in a little more with a laugh. "Even if it does you'd take it for me yeah?" He said and touched Senku's lips before leaning in to give him a kiss. "Hn- I would. Of course I would Tsukasa." He replied rolling his hips back to take in more of his lover. Tsukasa groaned and pushed in without being able to stop.
The sudden pain made Senku clutch the bedsheets and bite his lip. Tsukasa waited until his grip lessened to finally start going back and forth slowly. He watched the outline of his dick moving in Senku's stomach and pressed a hand over it making his lover scream. "Ahh! Tsukasa, harder! Stop holding back please-"
"Hn- Anything you want love." Tsukasa said and let go of his control. He grabbed the tiny waist with both his hands and pulled out almost completely before slamming himself back in making both of them moan.
Tsukasa couldn't hold himself back anymore and came inside his lover as he jerked off Senku with a strong grip. The sudden tightening as Senku came was enough for Tsukasa to get hard again.
He was going to pull out when weak legs wrapped around him. "Hmm keep going. There's a reson why I chose friday night for this you know?"
Tsukasa placed a hand on his cheek and asked with worry in his voice. "Are you sure? You look tired. I don't mind stopping now." Senku pulled his hair and fake pouted at him. "What, did you have enough of me now?"
"Senku, you're asking for it. You know better than anyone that I can't ever have enough of you." Tsukasa warned. Clearly aware that he was being provoked on purpose. Senku smirked at him and wrapped his arms around his neck. "Then prove it. Show me how much you need me."
Tsukasa let out a frustrated out a sound and pushed his hair back. "Fine. No more holding back. Don't complain when you pass out." He smiled innocently and reached down and pulled his sweatpants draw string off it.
Senku watched him blankly wondering what he was doing all of a sudden. He only realized when Tsukasa's hands went around at the base of his dick. "Wait! Why would-" Tsukasa silenced him with a particularly tight pull as he knotted the string around his cock tightly. He turned back to him with that damned innocent smile. "You won't enjoy it as much if you keep coming right?"
Senku grabbed his shoulder. "Wait. Won't you have the same problem then?"
"What are you talking about? I can barely stay soft when you're in front of me looking so perfect. I'll make sure to exhaust my stamina completely today."
Senku could feel himself twitch at the words. Not being able to cum unless Tsukasa allowed him was also turning him on more than he thought. A sharp thrust in his insides took him out of his head, he moaned and digged his nails in Tsukasa's shoulders. The fast and strong pace was making his eyes roll back.
The surprise came when suddenly Tsukasa hit a spot in him that made him scream and see the stars. His lover smirked. "Found it." He said and kept thrusting in the same spot.
Feeling it was much better than what he thought it would be. "Ah! Tsukasa please- I need to cum. Hn- It's soo good!" He said and tried to pull off the string around himself only for his hand to be pulled away. "No- You tried to take it off yourself. Did you think I'd let you? Too bad, I was about to take it off but now you'll have to wait more. You could do it for me right baby?" He said letting the pet name slip.
Thankfully Senku seemed to like it as he was trembling and dripping more with every second. The hand Tsukasa wasn't holding down was gripping the sheets in effort to not undo the string. "I will, I won't do it again so help me keep my hands away?" Senku asked him his eyes growing mosit with the pleasure and frustration of not meeting his release.
Tsukasa hummed. "Good decision baby." He said and watched Senku get red. He grabbed both of his wrists in one hand and tightened his hold enough to make sure he'd leave marks. Senku shuddered and Tsukasa resumed fucking him.
He only loosened the string when he came again, this time on Senku's stomach. The few firm strokes he gave Senku was enough to push him over the edge, leaving him heavily breathing and loose on the bed.
Seeing Senku's pale body covered in their cum was one of the most beautiful sights he's ever seen. His lover looked free and gorgeous lost in his desires when all he could think about was him. Being able to shut down Senku's always working brain was delightful. His best friend has never looked so peaceful and relaxed.
He could feel the blood rushing down again as he carved the image into his mind. He slowly started to kiss Senku, giving him a little time to recover before starting again.
The soft kisses transformed into bite marks and hands going along each others bodies before Tsukasa was once again slamming inside Senku.
The cycle kept going until Tsukasa realized Senku was barely keeping his eyes open. He quickly pulled out and was about to carry him to the bathroom before he heard a weak voice. "I wouldn't mind if you kept going. I'd like it if you just used my body whenever."
Tsukasa's eyes went wide. That sounded amazing. "Are you even awake enough to decide that?" He asked.
Senku's eyelids opened a little more to glare at him. "I wouldn't suggest it if I didn't think of it beforehand." He yawned and nodded off. Tsukasa smiled, who was he to refuse his lovers wishes? He placed Senku's head under a pillow and gave him a soft kiss before lifting up his lower half and entering back.
He checked to see Senku but he was still asleep. It almost made Tsukasa frown. Well, if he wanted to see his lover's cute reactions then he'd have to wake him up. He smiled and thrusted in. Now that Senku's moans were gone he could hear the sounds they made clearer. His skin slapping Senku's and the squelch of the mix of lube and his cum sounded obscene.
The unconscious and malleable Senku under him made him feel feverish. The trust Senku showed him as best friends was already surprising and now the one that came with being lovers made Tsukasa go crazy. To think Senku would be so vulnerable for him, both physically and mentally, made him fall deeper in love.
//
Senku woke up feeling more disorganized than ever. First he felt the usual, the soft bed and Tsukasa behind him with an arm over him, nothing out of ordinary. Then he woke up enough to remember how he fell asleep and what the strange fullness he felt was.
His eyes widened immediately and arousal flooded him. The ache of his body combined with knowing Tsukasa indeed used his body as he liked and he was still hard inside him even as he slept made him squeeze himself around Tsukasa.
Shit, he couldn't believe they were missing out on this. And to think he once thought he'd be the type that's married to their work. Not a chance now.
He slowly moved his arm and reached down to touch his stomach, feeling the outline. He pressed on it and squeezed at the same time, making Tsukasa groan behind him and move a little which in turn made him moan.
A soft hum came behind him. "You finally woke up and now you want more?" He said.
Senku shuddered at the breath on his ear and the deeper than usual voice. "I do. I think I missed out on a lot yesterday. Mind reminding me?"
Tsukasa bit his ear in response making him cry out. They did it once again before Tsukasa carried him to the bathroom. When he was placed down his legs gave out and he was caught by Tsukasa.
"I should've guessed you wouldn't be able to stand up." He said. Senku could see the smugness radiating off him. "So happy to be my vehicle and my chair aren't you?"
"Of course. Only for you." He replied with a smile and set him on the toilet before turning around to draw the bath.
Senku turned to look at himself in the mirror and saw how wild he looked. His hair was all over the place, he was covered in marks and bruises all over aside from his face. Well, he did now have a bite mark on his ear but it didn't really count. The handprints were turning purple where the bites and hickeys stood red like his puffy nipples did.
Ah, not to forget the cum he was covered in too. His hair, stomach and back were crusted in it. So Tsukasa liked seeing his face covered in his cum. Noted. Must've done it after he passed out.
He basically looked like he got attacked.
Curious, he turned to Tsukasa. Although he was careful to not leave any hickeys or bite marks as his lover couldn't wear much when fighting, he still managed to leave a handful scratches on his back. He could aslo see a faint redness around his waist, probably happened when he squeezed his legs around him.
He sighed and wished he too could bite him all he liked however that would place hia career on risk. He would get underestimated and worse, they'd try to find out who he was involved with. Tsukasa's life rarely ever included anyone but him and Mirai. He didn't want to think what could happen if they found out he was gay.
Well that was for underground fighting where things were always harsher. Maybe people wouldn't mind once he went pro. Lost in these thoughts he didn't realize the bath was ready until Tsukasa got in the warm water with him on his lap.
He let out a satisfied sigh and leaned on Tsukasa's chest.
"What were you thinking just now?" Tsukasa asked him and kissed his forehead.
"Just hoping I get to mark you up like this too." Senku smiled and showed his body.
Tsukasa hugged him tighter. "I'll be 15 soon and I already have offers coming up. Bear with scratches for now hm?" He said playfully.
Senku laughed. "I'll turn you into a scratch post by the time you're 15."
"You better. They already think I fight lions for fun it'll help my reputation." He laughed.
Senku turned around and placed his hair behind his ear before biting it softly. "This much would be fine right?" He asked touching his nose to Tsukasa's. A hand wrapped around his nape. "I'm glad I decided to keep my hair long."
He brought their lips together and licked into Senku's mouth. They pulled away before another round started and started to wash each others hair. Tsukasa carefully washed inside Senku too. He did it yesterday before falling asleep too, this time with Senku being awake it was easier.
They got off and Tsukasa left Senku to dry himself off as he changed the sheets.
Senku felt more relaxed than ever. Letting himself go was much better than he thought it would be. Tsukasa seemed to be on cloud nine too, his skin was glowing and he looked at him more affectionate than ever, something Senku didn't think was possible. He could tell Tsukasa enjoyed being relied as much as he enjoyed letting himself go.
He was curious why they enjoyed it so much on a psychological level too but for the first time he didn't feel like immediately doing a research. He was quite satisfied where he was, wrapped in a soft towel with his body aching sweetly.
//
That night, when they curled up on the bed together, Senku realized he already knew the answer, although nothing scientific.
"You know, you're the one that made me this way." He said.
A silence followed. Tsukasa answered. "You aren't soft enough to mold at my will Senku. You chose it on your own, although I paved the way."
Tsukasa was always fast to pick up on what Senku was talking about. Almost as if they were one separated into two.
He hummed. "We could've been normal." Senku said.
"Maybe. But I know that'd be never enough for us. I always treasured you too much for us to turn out normal." Tsukasa replied. Senku chuckled. "I don't hate this at all." The arms around him tightened. "Me too."
Senku knew it wasn't normal to enjoy the bruises on his torso burning again at the tight grip but he couldn't help it.
Ever since they first met Senku knew Tsukasa was different. He seemed closed off compared to other kids surrounding them. Tsukasa was mature in ways like himself when others could still enjoy being children.
Senku realized quick enough that Tsukasa was possessive. Once he'd decided something was his, he wouldn't allow anyone else close. Senku knew yet allowed Tsukasa to pull him away from others.
How could he not like being wanted by him when all the other kids were so bland? Those kids could only look at him with pity and confusion when he talked about his family when Tsukasa could understand him.
Senku enjoyed being wanted too much. He purposely pushed Tsukasa to his limits by hanging out with others, lying to him when he knew Tsukasa knew the truth, ignoring him for his researchs. And never once did Tsukasa decide he had enough of Senku, no, he'd do anything he could to steal his attention.
Senku could tell Tsukasa liked it, proving over and over again that he wouldn't leave him alone.
Just as he tested him, Tsukasa would also test him. He'd beat the kids he talked with in front of him, waiting for a reaction. Senku would watch him punch and kick his classmates with a smile on his face, never once stopping him.
When Tsukasa was satisfied seeing that he truly didn't care about anyone else, he'd stop and they'd go home hand in hand.
It really was no wonder all of these ended up reflecting on their intimacy, taking it all a step further.
Senku chuckled. "And to think you didn't know we were dating. Did you really think you could give me up for someone else?"
Tsukasa laughed with him. "I was too focused on owning you to think that it might mean dating. You think you could've ran away from me?"
"I would never." Senku said with a smile and placed a hand on Tsukasa's arm, softly caressing.
//
Senku huffed and turned his face to his boyfriend.
"These popular articles aren't reliable at all! They trace back to philosophy and fake sources most of the time. So annoying." He pouted and closed yet another website on his computer.
Tsukasa placed his chin on top of his head and adjusted Senku higher on his lap. "I'm still happy that the 'kinks are genetic' one was fake." He replied.
Senku let out a small laugh. "I guess I should've expected these ridiculous things mixed in with this type of a subject." He took a moment to tap his fingers on Tsukasa's arm as he thought. "Would you mind if I talk about it with Xeno?"
Tsukasa hummed. "Sure."
Senku rised a brow. "That was suspiciously quick."
"You'll be saying that you belong to me to that guy with your own mouth, I actually quite like that so go ahead." Tsukasa said placing a kiss on his hair.
"Possessive much? At least Stanley is as over the top as you are so I can talk to Xeno without being embarrassed." He said and quickly started to text his mentor.
Tsukasa hummed. "If that Stanley you mentioned is also into martial arts I think there might be a pattern."
Senku chuckled. "10 billion percent correct. Although it's probably because of our collectively weird lives that we have so many similarities."
"Just so you know I'm still weary of them." Tsukasa said.
Senku lightly, or maybe with his full strength, punched his arm. "Fine, fine, I didn't forget."
Notes:
They fucked!! Yayyy! This is a huge chunk of my already written parts so the next chapter is gonna be fresh out of the oven but later than normal bear with me pls I hope everyone enjoyed!! 💕
Chapter 5
Notes:
Hi! I know I've been gone for a long time but ao3 curse striked again, my parents are getting divorced. On my exam week too. I hope everyone enjoyes the new chapter tho!!!
(See the end of the chapter for more notes.)
Chapter Text
Tsukasa was in deep trouble.
There was only a week left for Senku's birthday but he still couldn't find a present he wanted to give him.
The money wasn't even the problem since he'd been saving up for this for quite a while, just that he couldn't find anything suitable.
His first thought was buying him a fancy set of chemistry supplies but a phone talk later he found out that Byakuya already chose that as his present.
The next was a small and expensive motor for their mini rocket experiments but when Tsukasa mentioned 'how amazing their experiments would be if they had such a thing' Senku smiled and showed off Byakuyas Nasa credit card information and let Tsukasa know he already ordered one online.
So now, with no new ideas, Tsukasa was searching through Senku's room to see what he might ne lacking as the boy was in school.
It wasn't long before he sat down on their bed with a sigh. He did know a lot about Senku's scientific instruments by now, but he still couldn't tell what he might need for his future experiments. He could always look through his texts with Xeno but sadly his English was lacking in the jargons they loved using.
He frowned and said fuck it before sitting down in front of Senku's desk and opening up his messages.
Just under his and Byakuya's contact stood Xeno's number.
Seeing that the older man was active, he didn't waste any time and FaceTimed him, not wanting to leave text messages as a trace or go through the motion of explaining everything by typing.
The call was picked up but the screen showed an unknown man's broad naked chest, quite built if he had to admit, with dog tags and barely a chin.
"Kid, Do you know what time it is-" The man stopped talking and quickly lowered his face enough to see the screen. "Who the fuck are you?" The amber eyed man asked.
"Is Xeno avaliable ot not?" Tsukasa asked curtly, he was annoyed enough that he had to call Xeno and now he had to deal with this random man and even more than that, knowing that if Senku was the one calling he'd be facing a half naked man angered him enough.
The blond man took a drag from his cigarette while glaring him. "What's your business with him?"
"Nothing that concerns you." Tsukasa shot back.
The older took a slow drag before responding. "So you're that genius kid's boyfriend." He continued when Tsukasa didn't reply. "Xeno might get mad at me for ignoring something related to his star pupil later so I'll give you a chance to state your business before I hang up."
Tsukasa hummed. "I see, so you're Stanley." He took a moment to consider. "This isn't bad, you might actually be more of a help than Xeno." At the blond's raised brow he continued. "I'm searching gifts for Senku's birthday. I'm sure you'd know what a scientist would like for a present."
Stanley smiled a little and hummed. "I do know a few things about what a genius likes." His smirk widened, "You're lucky since I read their recent messages."
Tsukasa smiled back, maybe this guy wasn't as bad as he thought.
By the time their call ended, it was late enough that he had to text Senku that he might be later than usual.
Although by late, he meant that he wouldn't be able to stand at the school's entrance menacingly for 15 minutes until Senku came out.
It was just one of his tactics to make sure Senku wouldn't get bullied. Thankfully the threat of a really tall and muscular friend who didn't attend school was enough to scare away most and if it didn't... well, Tsukasa would pay it back tenfold.
The worst he's done so far was beating up a kid who wrote 'nerd' and 'fag' on Senku's desk in front of his whole class until he peed his pants and then making him lick off the writings.
He smiled at the fond memory and took his place at the school's entrance.
The teachers around quickly avoided his gaze when they met his and walked quicker.
Tsukasa had his fair share of teachers to deal with too. Some of those idiots couldn't stand a kid being smarter than them and correcting their lessons. He was a lot smaller back then but now his mean glare was enough to make the adults shy away.
He crossed his arms and glared at everyones passing by until Senku greeted him. Tsukasa smiled and placed a hand on Senku's nape.
When he turned them to the opposite direction of their home Senku rised a brow. "Where are we going?"
Tsukasa smiled. "I'm taking you to watch my match. An early birthday present." Senku smiled brightly at that. Tsukasa usually never wanted to take him to his matches saying it was dangerous. "Really? I'll cheer you on the hardest!" Senku said.
Tsukasa chuckled and took Senku's bag from him to slip it onto his empty shoulder.
//
The place was almost full by the time they arrived. Senku could hear the crowd even when they entered from the back.
Tsukasa greeted few people and walked into the locker room. It was empty aside from 2 people in the shower rooms.
Senku sat down on the bench and watched as Tsukasa undressed. He would never tire from seeing Tsukasa's muscles. Not a single place on his body was left undeveloped, his fat percentage was low enough to see clearly how his muscles rippled with his every move.
As he watched not even trying to hide it, he noticed Tsukasa smiling slightly and pulling up his shorts before sitting down next to him and handing him bandages. "Wrap them for me?" He asked.
Senku smiled and did so and watched Tsukasa go through his warming up.
Knowing that his Senku was watching his every move, Tsukasa couldn't help but put on a show for him.
As the time for the match came closer Tsukasa instructed Senku to take a seat instead of going with the cheering crowd, not wanting his small boyfriend to get crushed by the people or get into that mess of sweaty people touching him. He also reminded Senku to not talk with anyone which he got a mocking look in return. "Byakuya taught me stranger danger when I was 3 Tsukasa. Stop worrying so much and go." He ended his annoyed talk with a smile.
Tsukasa nodded and walked out of the locker room with Senku following behind just far enough to take a seat.
Tsukasa was welcomed with the usual cheers and screams of telling him not to lose. He placed in his mouthguard. The only protective gear he was allowed to use.
His opponent looked at him with a sly smile as he waved at the audience. "I'll make anyone who placed bets on this little kid regret!" The bald man screamed and received the attention he was looking for.
Tsukasa smiled to himself, he always liked crushing down cocky opponents. The buzzer went off and Tsukasa stood at his place. Motioning the other man to come close with two fingers. The bald man raged in for a punch as the crowd roard. Tsukasa evaded the slow blow and delivered a one his own right under the man's chin, knocking his opponents head up and making his lips bleed with the impact.
Then he once again retreated calmly waiting for the man to collet himself and attack him again. His fans were screaming in joy. "He's playing around! That guy is so dead!" Tsukasa smiled. It wasn't usual for him to drag things out but today, he didn't have a Senku waiting at home for him. He had his love right there watching him with wide eyes. Tsukasa would make sure it'd be the bloodiest fight. He couldn't waste Senku's early birthday present with just a few quick punches now could he?
He played with the man until the white bandages Senku wrapped on his hands turned deep red. The floor became wet with blood, sweat, vomit and piss. Without anyone to stop the matches when it started to get too far like in legitimate matches, it wasn't unusual for human body to leak out in various liquids as they got beaten with small breaks in between.
Thankfully the wet ground was not something that could make Tsukasa slow down. His balance and callouses were too developed to slip. His opponent, however could barely stand let alone take a steady step towards to him. Well, the guy probably couldn't even see where Tsukasa was after all that beating.
Letting out a dissapoined sigh, Tsukasa decided to give the man a good punch just below the ribs to knock him out and end his show.
The crowd was still high on the exceptional beat down they watched as Tsukasa was finally announced the winner. He raised a bloody fist up in the air with a charming smile as he tried to glance at where Senku was. He could barely catch the ruby eyes wide in amazement but it made his heart skip a beat.
Despite wanting to rush towards to his boyfriend, Tsukasa calmly made his way back to the locker room while ignoring people around him trying to get him drinks and shouting over each other about how amazing he was. Thankfully his audience wasn't dumb enough to keep persisting when Tsukasa gave them no attention.
The moment he stepped in the private area, his head was yanked down by his hair and his lips were met with soft ones. At the familiar touch and his already fired up state Tsukasa didn't resist and picked up Senku by his tiny waist, making the smaller wrap his legs around him as their kiss turned sloppier.
Senku's hand were all over his chest and arms, digging his short nails into his muscles as if he couldn't have enough while his mouth was busy sucking Tsukasa's tongue. The clear desperation and the noises Senku made Tsukasa feel as if he was drunk.
Having Senku's chest against his and not being able to tell the difference between their equally loud heartbeats, the taste of Senku's sweat and spit in his mouth, his hands just under Senku's thighs... All these sensations were enough for Tsukasa to almost cum in his shorts.
Just as he switched to holding Senku with a single arm and moved the other to his lover's pants, a loud knock on the door behind them made him freeze.
"Hey- did you lock the door?" A voice asked as the doorknob moved.
"Shit." Tsukasa muttered. Of course the guy he just beat up would have to clean up in here before leaving. He sighed and took a look at Senku, who had a hazy gaze.
"Are you alright?" Tsukasa felt the need to ask before letting him go.
Senku nodded. "Yeah. You can let me down."
Tsukasa did so and waited until Senku sat down on the bench with his face turned away from him until he opened the door.
"Finally! Why did you even lock it for? Was a fan getting persistent?" One of the staff asked him as he hauled the beaten man inside a shower stall.
"Something like that." Tsukasa answered vaguely. Thankfully his boner vanished at the sight of others.
He ignored the two and sat down next to Senku as he started to unwrap his hand. "I'll take a quick shower hm? Wait for me here." Tsukasa instructed, noticing that the dazed state Senku was in taking a little long to dissipate.
He waited until Senku muttered a yes to walk into the cramped shower stall and wash up quickly as he could. When he left he was met with a grumbling Senku who was going through his bag.
"Wha- Oh." The brunet stopped himself from asking as he saw the huge hand print shaped blood stains on Senku's pants and shirt.
Senku turned to him as he scoffed. "If we already didn't have hydrogen peroxide I would've made you pay." He said as he took out Tsukasa spare change of clothes.
"Really? I remember someone being just as desperate." Tsukasa mocked while Senku grumbled under his breath about how much bacteria blood had.
Tsukasa had hard time taking his eyes off Senku in his clothes. His red t-shirt's short sleeves were coming down to Senku's elbows and his gym short's drawstring's were in a huge bow because it fell off otherwise, which Tsukasa had a good laugh as Senku blushed.
Despite laughing about it just a few seconds ago, he now wanted to eat Senku up and he would. Once they returned home that is.
//
"You're crazy." Senku said. "I kinda forgot how merciless you were."
Tsukasa hummed. "Maybe I should take you with me more often then."
Senku rolled his eyes. "Like hell you would keep taking me to that sketchy place."
"I would beat up strangers on the side of the road if you'd look at me like that again." Tsukasa admitted with a shrug.
"Yeah. Yeah. Calm down now Lion boy. I guess I don't need to raise your ego even more with praises, but do you really fight like that everyday?" Senku asked.
"Hm, I admit that I went extra today for you but it wasn't too far off from my usual. I tend to play around less when I have you waiting for me at home." He said with a charming smile, which made Senku get a little hot.
"I love you too." He replied which earned him an affectionate kiss on his cheek.
"I'm still making you wash my clothes though." Senku added.
"If I don't will you keep wearing my clothes?"
Senku punched him on his arm. "It's my school uniform dumbass!" Tsukasa laughed as Senku continued.
"Just so you know... You were really amazing today." Senku spoke up after a while with pink cheeks as his hand clenched on Tsukasa's sleeve.
Tsukasa's laughter softened into a fond smile. He leaned down to kiss Senku's temple. "Now you know how I feel watching you do experiments."
Senku smiled back at him. "I can't believe I'm saying this as a scientist but I think you were made for me."
Tsukasa's eyes widened. "But you always make fun of people saying cheesy things like that?"
Senku scoffed. "Yeah it's ridiculous I know. But I just don't think we could ever not be together. It's probably our slowly increasing degree of codependency talking but-"
Senku's words were cut off by Tsukasa lifting him up in his arms to give him a kiss, at least as much as he could while his lips were stretched in a bright smile.
"I think we're made for each other too." Tsukasa hummed and gave him another peck. "I don't think I can breathe without you."
Senku chuckled in response as he cupped Tsukasa's face in his hands. "Yeah? Good thing I'm not leaving you then."
The brunet's hands tightened around the small body. "I wouldn't let you anyways." The words that would've been a threat sounded like a confession to Senku.
Tsukasa walked back home all the way, still carrying Senku in his arms in the empty streets.
Notes:
Another chapter full of fluff! And I obviously have 0 idea on fighting much less illegally so excuse my mistakes pls!! Lol