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It was getting dark, and the temperature began to drop.
It was one of Izuku’s favorite kinds of weather.
He was finishing a patrol in the city, heading toward the subway to return to U.A. It was a bit crowded, but he managed to slip in and find a decent spot to stand.
The ride was peaceful. He took the time to organize his anxious thoughts.
After the war, his friendship with Katsuki had improved a lot. Now they had one day a week to hang out together—maybe it was Katsuki’s way of making up for everything he had put Izuku through, but Izuku preferred to think it was to make up for lost time.
His friends were making great progress. With the evolution of their skills, they had become worthy heroes.
His thoughts were suddenly interrupted when the train made a harsh stop, causing passengers to stumble. One in particular fell against him, almost knocking them both down, but Izuku caught the person and steadied them before they could fall.
“Hey, are you okay?”
The person had a hood covering their head, so Izuku couldn’t tell if it was a man or a woman.
“Y-yeah, thank you.”
It was a man, though a bit shorter than Izuku. He was about to say more, but the man quickly stepped away and disappeared into the crowd. That left Izuku confused, but he shrugged it off.
A soft voice came over the train’s speaker, apologizing for the sudden stop, and soon the train resumed its course.
It took 30 minutes to get back to U.A. Even though he’d only caught a few small-time thieves and helped some citizens with everyday problems, he felt exhausted.
When he arrived at the dorm, there were only a few people around. Since the war, most of the class had started visiting their families more often. Today happened to be the day most of them were away, and if he wasn’t mistaken, Katsuki was supposed to return today from his parents’ house. Tomorrow would be their day together, and Izuku was looking forward to it.
He greeted Mina and Jiro, who were chatting on the couch. He didn’t stay to talk; not only was he tired, but he also wanted a nice, long shower.
He went to the bathroom, undressed, turned on the shower, and stepped under the water. The heat instantly relaxed his muscles, and he enjoyed the feeling of the water running down his body—until he felt a sharp pain in his arm. Looking down, he noticed two small puncture marks, though there was no bleeding. Izuku had no idea what it was, but ignored it since it didn’t seem serious.
After finishing his bath, he collapsed into bed. He was so tired that he fell asleep the moment he lay down. It seemed like it was going to be the best night’s sleep ever.
⸻
This was the worst night’s sleep of his entire life.
It started with a headache, which Izuku assumed was just from exhaustion, so he ignored it. But it kept getting worse until he got up, went to his small first aid kit, grabbed a painkiller, and swallowed it dry—he didn’t feel like going to the kitchen just for a glass of water.
He lay back down and tried to sleep again.
But the night had other plans for him, and none of them were good. The headache spread through his entire body. What the hell? He had just taken medicine for that! His body felt hot and cold at the same time, and the pain wouldn’t stop. Izuku panted in agony, curling up in the fetal position on his messy bed from tossing and turning so much.
He felt bile rise in his throat and quickly grabbed the trash bin, throwing up the acidic contents of his stomach—reminding him he hadn’t eaten before bed. He’d been so tired that he forgot.
Then the pain moved to his mouth. Something was happening to his teeth. When he touched them with his tongue, pain shot through him—but he could tell his canines were sharper, longer. Or maybe he was just delirious from pain.
He needed help.
But who would be awake at this hour? Uraraka and Iida had gone home, along with Tsu and most of the class, especially the ones he was close to. And he didn’t want to bother Aizawa-sensei; the man already had enough to deal with and would be in a terrible mood if Izuku woke him up.
The only person who might still be awake and that he was familiar with was…
A notification sound filled his dark room.
Gathering some strength, he reached for his phone on the desk—and saw a message from the person he had just been thinking about.
Kacchan.
The message asked if he was okay because Katsuki could hear some banging on the wall.
Oh god, he was doing that? That explained why parts of his body were sore. Izuku wanted to throw himself off a cliff.
Kacchan had ended up becoming his next-door neighbor.
Now Izuku felt guilty for disturbing him. He replied, saying he was fine and had just hit the wall by accident.
Not the best excuse, but it would have to do.
He went back to his first aid kit and took another pill, this one stronger, swallowing it quickly. Then he wrapped himself tightly in his blankets like a cocoon—it was one of his almost failproof methods for easing pain. It worked a little; the pain dulled in some places.
That lasted about 20 minutes before he finally felt relief, and then he passed out from exhaustion.
⸻
The next morning, the alarm clock woke him.
He wished his past self had remembered to turn it off—he had no class today, no patrol either. With a groan, he hit the button and buried himself back under the covers.
But luck wasn’t on his side.
Three knocks came at the door. He would’ve ignored them, pretending not to hear, if not for the louder, more impatient knocks that followed. Izuku immediately knew who it was.
Dragging himself out of bed, feeling like his legs were made of lead, he shuffled to the door. Turning the knob, he was greeted by a familiar blonde head.
“Damn, you look like you got hit by a truck.”
Kacchan, delicate as ever.
“Thanks, I worked hard to look this bad,” Izuku replied with a half-smile. Their conversations had changed a lot—they could now throw sarcastic and offensive comments at each other freely.
The blonde snorted in amusement, but the smirk quickly turned into a worried frown.
“I’m serious. You sick or something?” Katsuki had that mysterious ability to know when Izuku was hiding something or wasn’t okay—and no, it didn’t make Izuku’s heart feel warm. Not at all.
Izuku sighed.
“Didn’t sleep well. Honestly, getting hit by a truck might’ve hurt less,” he admitted, inviting his childhood friend inside.
The room was still dim, and Katsuki went to open the curtains, flooding it with sunlight. Both of them squinted, but soon adjusted.
Izuku sat back on his bed while Katsuki took the chair by the desk, facing him.
“Your room’s a mess too. What the hell happened?”
“I’m not really sure. Yesterday was normal. Nothing weird happened.” Izuku spoke thoughtfully, trying to replay the day in his head.
“Seriously? Then it’s probably just stress or some crap like that. I came here to drag you out of this dump and make you eat something. You didn’t eat when you got back, and that might be why you’re like this.”
The blonde stood up, walking toward the door. “Get yourself ready. I’ll make us breakfast.”
And with that, he left the room.
Was it a good idea to talk to him? Well, he didn’t blow up his face, so that was already a win.
Izuku went to the bathroom to brush his teeth and take care of his morning routine. He noticed his skin looked paler than usual, and when he looked in the mirror, he finally understood why Kacchan said he looked like he’d been run over by a truck.
He turned on the faucet and splashed some water on his face, trying to wash off at least a bit of the tiredness. Then he prepared his toothbrush—but as soon as he put it in his mouth, something felt wrong. Izuku opened his mouth in front of the mirror to see what it was and noticed his canines—huge, sharp. The boy flinched and immediately closed his mouth, but that only made him bite his tongue, drawing blood.
He tried to spit out the blood pooling in his mouth—but he didn’t. His body refused to obey. He tried to spit, but his mouth wouldn’t move the way he wanted. And before he knew it, he swallowed it.
From that moment, everything inside him changed.
The taste of blood wasn’t metallic—it was… sweet. With a faint salty touch.
But what really scared him was the hunger that twisted his stomach so badly it hurt. Izuku licked the wound on his tongue again, tasting a bit more of the blood, and swallowed. Again, that strange, pleasant flavor—and the sharp pain of hunger tightening inside him.
Luckily, Izuku was smart enough to realize something: drinking blood didn’t just taste different—it actually eased his hunger.
Terrifying.
What the hell was happening to him?
Had he been hit by someone’s Quirk? But he didn’t remember being attacked, and the thieves he caught all had passive Quirks, so it couldn’t have been them.
Then who?
Unless…
Ah.
The man on the subway. It had to be him—the only person Izuku had physical contact with. He had seemed suspicious, but Izuku had been too tired to care at the time.
Still, even knowing who it might have been didn’t help much if Izuku hadn’t seen the guy’s face. It could take weeks to find him in the system—if he even had records there.
Izuku’s thoughts were interrupted by the sound of the door opening—Katsuki coming in with breakfast.
How thoughtful, Izuku thought for a second.
“You still at it? What, were you taking a dump or just started brushing your teeth now?”
Forget what he said.
“Kacchan, I think I know what happened!” Izuku blurted out, feeling both nervous and tense. Katsuki’s expression shifted to something between worry and confusion.
“Then spill it.” The blonde set the breakfast down on the desk and crossed his arms, sitting again.
“Before I came back, the train stopped suddenly, and everyone stumbled. One guy fell on me—he seemed suspicious now that I think about it. I asked if he was okay, he said he was, and then disappeared into the crowd.”
“When I got back, I was exhausted, took a shower, went to bed… then in the middle of the night, I had a splitting headache. Took medicine, didn’t help, and my whole body hurt.” Izuku paced back and forth at the bathroom entrance while Katsuki listened—patiently, for once.
“Get to the point, nerd!” Okay, maybe not that patiently.
“My teeth started hurting, and I thought I was imagining things, but now my canines are bigger.”
To prove his point, Izuku opened his mouth, showing the sharp fangs.
“The hell is that?” Katsuki got up, leaning closer to inspect. The fangs were definitely longer—unnaturally so.
“I even bit my tongue by accident and started bleeding. I tried to spit it out, but I couldn’t—and when I swallowed, I realized the blood actually fed me somehow. So whatever this Quirk is, I think it turned me into some kind of vampire.”
They both went silent for twenty long seconds.
Then Katsuki snorted—and burst out laughing.
“You’re kidding me, right? I lived to see this—Izuku Midoriya turning into Count Dracula.” The laughter got louder until he was holding his stomach.
Izuku stared at him blankly.
“I’m serious, Kacchan! If I really need to feed on blood, where am I supposed to get it from?! I can’t just go around saying, ‘Hey, can I drink your blood? Some cursed Quirk turned me into a vampire and now I’ve gotta deal with this crap!’ That’s insane!”
Katsuki laughed even harder.
“God, I’m gonna die laughing,” he said between breaths, still chuckling for a good three minutes before finally calming down. “Maybe it’ll pass soon, nerd. You won’t stay like this forever.” He tried to sound comforting—but a few more snickers slipped through, making it less convincing.
“The problem is we don’t know how long this’ll last, idiot!” Izuku snapped, irritated that Katsuki wasn’t taking it seriously.
“Hey! I’m just saying you need to chill. This blood thing might all be in your head—you’re probably just starving because you haven’t eaten since last night. So eat the damn breakfast already.” Katsuki handed him the food, and Izuku cautiously took a bite.
It was scrambled eggs and toast—his third favorite breakfast.
He chewed, swallowed, and waited for nausea or something weird to happen—but nothing did. Relief washed over him, and he quickly ate the rest.
Thank goodness normal food still worked; he would’ve been heartbroken if he couldn’t eat his favorite meals anymore.
When he looked at Katsuki, the blonde was wearing that face Izuku hated most—the “I told you so” face.
“Hope that helped with your anxiety, nerd.”
And, whether he wanted to admit it or not, it did. Izuku felt calmer. Maybe he was overthinking, maybe—
His stomach twisted again.
At the same time, nausea and hunger hit him.
“I’m still hungry,” he said flatly, looking at Katsuki.
“Shit.”
The blonde stood, grabbed the empty dishes, and headed toward the door. “Come on, you’re not staying locked in here today. We’re going to see Recovery Girl—maybe she’ll figure out what the hell’s going on with this freaky Quirk.”
He didn’t wait for an answer and left.
Izuku blinked, then followed him to the kitchen, where Katsuki set the dishes in the sink and started washing them.
Izuku sat at the counter, watching him. He didn’t regret telling Kacchan about what was happening. Even with the teasing, Katsuki was helping him stay grounded. Izuku was honestly grateful for how much effort the blonde was putting into mending their relationship.
“Damn it!” Katsuki’s shout snapped him out of his thoughts.
Izuku looked up to see the blonde holding his finger—bleeding.
Blood.
Hunger.
Need blood.
Izuku’s mouth watered. Before he realized what he was doing, he moved closer, eyes fixed on the cut. Katsuki gave him a puzzled look—until Izuku suddenly grabbed his hand and put his finger in his mouth.
“Hey! What the hell are you doing?!”
Katsuki cursed, struggling to pull away. “Damn it!”
It took effort, but he finally yanked his hand free.
“What the hell is wrong with you, idiot?!” Katsuki shouted, furious—and a little shaken. Izuku didn’t answer. For a moment, the blonde’s anger faded into concern. “Hey… you still there, nerd?”
He stepped closer—just as Izuku lunged, knocking him to the floor.
Izuku was on top of him.
“S-sorry, Kacchan… I can’t hold it back. It’s too strong…”
Izuku trembled, biting his own lip hard enough to draw blood, his nails digging into the floor as he fought his own instincts.
Katsuki shifted, using his strength to flip their positions—now he was on top, pinning Izuku down.
Izuku didn’t fight back. That was… something.
“Hey, Izuku, listen to me. You think you can hold on long enough for me to get to my room and take care of this cut?”
It took a few tense seconds before Izuku finally nodded weakly. Slowly, Katsuki let go and backed away, heading to his room.
Izuku stayed behind, struggling against the overwhelming hunger. The scent of blood coming from Katsuki’s room made it impossible to think. He had to get away—but his body wasn’t listening.
Before he knew it, he was already moving toward the other room—his body acting on its own.
The door burst open. Izuku lunged.
Katsuki barely managed to dodge, and suddenly they were in a chaotic chase around the room—Katsuki yelling at him to control himself, Izuku shouting that he couldn’t.
Eventually, both were out of breath. Izuku caught Katsuki and they fell onto the bed, panting heavily.
The room was dim, but Katsuki could see the look in Izuku’s bright green eyes—pained, desperate, on the verge of tears. He understood then that this wasn’t just hunger; it was the situation itself breaking Izuku apart.
Katsuki exhaled sharply, then made a decision.
“Hey, Zuku,” he said softly, voice calmer now. “How about this… I’ll give you a little of my blood—but not too much, just enough to stop that damn hunger from eating you alive.”
Izuku was still breathing hard, trembling—but he nodded.
Katsuki tilted his head, exposing his neck. He felt Izuku’s breath first—sending chills down his skin—then the sharp sting that followed. It hurt, but not too much. He could feel Izuku drinking carefully, like he was trying not to hurt him.
Katsuki almost laughed at the thought.
Of course the nerd would even drink blood carefully so he wouldn’t cause pain.
He was the kindest person Katsuki knew.
In reality, the blond just wanted to think about other things so he wouldn't feel the other's tongue on his neck giving him sensations he had never felt before, or the way his breath made him shiver, or the position he was in with Izuku sitting on top of him right on his...
No, no, no, no, no, no.
NO
Katsuki felt him growing, he needed to think about other things quickly or else he'd get fucked in the ass.
And as if his prayers had been answered, Izuku stopped sucking him, but not before running his tongue over the possible “wound” from his teeth. That destroyed Katsuki.
When the blond looked at the green-eyed boy, he was a little scared. He had never seen that expression on the boy's face before, he was in pure ecstasy and his bright green gaze was like that of a predator capturing its prey.
Damn, he couldn't deny that Izuku was incredibly beautiful like that.
Fuck.
Think about something else, think about something else!
“What's wrong, Kacchan?”
What the hell? Where did he learn to speak in that soft yet sensual tone of voice? What a disaster. Katsuki was in deep trouble.
“N-nothing, are you done?” He tried to change the subject and Izuku got off him before things got any weirder than they already were.
“Hmm, not yet.” He had the nerve to pretend he was thinking. What else is missing?!
“If you still need more blood, you didn't have to leave before you were satisfied.”
“But I am satisfied. I'm talking about this.” The son of a bitch had the nerve to sit back further and got on top of...
Damn it!
Don't grow! Don't grow!
“Why are you doing this? You're going to have serious problems if you don't let go.” “ Izuku leaned forward and got close enough for their noses to touch. ” I don't think it's fair, Kacchan helped me, so I'm going to return the favor. " It was so sudden that Katsuki didn't have time to react, he just felt Izuku's soft lips against his in an innocent peck that seconds later turned into a wild kiss.
Their tongues fought to see who would take control, and without realizing it, Katsuki put his hands on Izuku's rosy cheeks and pulled him closer like a magnet.
In an instant, the blond changed positions, getting on top, and Izuku quickly embraced him, deepening the kiss. The smacking sounds of the kiss could be heard along with their sighs. But they had to separate to breathe again.
“Thanks for the meal, Kacchan.” Izuku gave a cheeky, toothy smile, and Katsuki went crazy at the sight, damn it.
And then he feels hands moving on his pants. And then going to—
Katsuki let out a moan. Izuku's warm hands covered half the length of his cock, the blond risked looking at him and saw him making the most innocent face anyone could make, as if he wasn't jerking him off.
"Kacchan, as always, you're amazing at everything. Your cock is so big that I need to use both hands to hold it all." Izuku flattered Katsuki, and that made his cock throb with excitement.
The green-haired boy began to move back and forth after getting on top of Katsuki. He was sitting on his legs with his torso lowered where he could see the blond's face and his cock at the same time.
“Damn, what got into you to get like this, Zuku?” The blond let out a small moan when Izuku caressed his head. “Hehe, I liked that.” He smiled, and it seemed to affect Izuku because now he opened his mouth and ran his tongue over the head of his cock.
Katsuki was in heaven, and it was just a lick, he couldn't imagine what it would be like to have his mouth swallow his entire length.
“Damn.” He sighed when Izuku stopped moving and took him in his mouth, starting to suck him.
It was a fucking perfect sight, Izuku looking at him with teary eyes, his green eyes shining, and his cock disappearing into his mouth. He also noticed that the green-eyed boy was rubbing himself against his leg, and he could feel the wetness coming out of his shorts and wetting the blond's pants.
All of this together was already good, but Izuku decided to add more by grabbing the base of the cock and sucking the head, which was really tasty. But he was also reaching his limit.
“Damn, Zuku.” Katsuki tried to speak but couldn't, and they both moaned loudly as they reached their peak. When the blond looked at Izuku, he was a mess, his cock throbbing inside the other's hot mouth, spurting semen, spasming a few times and breathing heavily.
Izuku took the cock out of his mouth, but not before opening it and showing the white liquid to Katsuki and swallowing it. Damn, that was fucking awesome. He crawled closer to the blond and kissed him, not a desperate kiss, but something deeper.
“I hope I satisfied you, Kacchan,” the boy whispered after they stopped kissing.
“I wasn't expecting it, but it was good,” he whispered back. Izuku looked like he was about to pass out from sleep, so the blond hugged him and turned so they were side by side.
Izuku snuggled into his chest while Katsuki rested his chin on his green hair, giving him little kisses. They both took a nap clinging to each other.