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Katsuki shuffles in irritation behind Deku. His mother had called to yell at him to walk home with Deku for their winter holiday. Auntie Inko had called her in tears, worried about the nerd getting attacked on his way home as they would be walking home after school in the dark. What a baby. Anyway; now that he knows the nerd has All Might’s power, he’s sure that Deku hardly needs Katsuki to waste his time walking with him.
“H-hey, Kacchan.” the nerd stammers nervously. “What are your plans for the winter break? I thought you would have stayed at school for extra training in the gym.”
“The hag is making me come home and have family time.” Katsuki snorts. As if he wants to do that. He will probably spend most of his break working out in their home gym and locked in his room.
As if to signal to the nerd that the conversation is over, Katsuki puts his earbuds in and turns his music up loud. He glances at the nerd, who shrugs and continues walking toward their homes.
Katsuki shifts his heavy backpack, full of laundry for his mother, to the other shoulder. Thrown off-balance, it slides off and falls to the ground. Katsuki curses and leans down to pick it up just to hear Deku cry out.
“Kacchan! Look out!” Katsuki assumes a defensive stance but doesn’t see anyone around. Including Deku. Where did the nerd go? His ugly yellow backpack is lying on the ground where he was standing.
“Oi! Deku! Where the hell are you?” he shouts, removing his headphones and turning around, fists cocked in front of him. A few passers-by on the street glance his way and rush off hurriedly to avoid getting involved in drama. Shit. He didn’t see where Deku went. Was he sucked into a portal?
“Auntie’s gonna kill me.” he mutters. Let alone All Might, who has trusted him to keep an eye on the nerd.
“Hey! Shitnerd!” he yells again, panic starting to grip his stomach. Fuck. Snow is beginning to fall, and the city is quiet under an increasing white blanket. He hears the sound of a cat yowling in a nearby alley and a garbage can falling over.
He picks up his and Izuku’s backpacks and dials 110, as well as fires off a quick text to All Might.
> Something happened to Deku
As he hits send, he hears a creepy purring sound in his ear as someone taps his shoulder. He flips his head to look at the noise source, and everything fades to black.
***
“What the FUCK!” Katsuki wakes up thrashing. He is in what appears to be an enormous garbage can. It smells so, so bad. Katsuki can TASTE the smell, and it’s horrifying; it feels like he’s breathing in the aroma through every pore in his body.
“Fuck, fuck, fuck!” he curses and thrashes around. The garbage can tips over onto its side, and he tumbles out along with some garbage bags. He gags a few times and tries to orient himself while lying on the cold ground. His eyes feel weird, and he can see all around him in the dark alley. It almost feels like he’s wearing night-vision goggles. He must have been hit with a quirk. He knows the drill and does the self-scan. He’s breathing and not in pain; check. He has already confirmed that he can speak. Check. He looks around for his bag and phone. Gone, shit, he’s been robbed. Okay, he thinks, let’s check for bleeding or bruising. As he stretches out an arm to investigate, he lets out a scream.
***
“Kacchan.” Izuku thinks when he hears the scream. It comes from the same alley where he found himself. Kacchan must have been dumped there too! Izuku wonders if he’s just figured out what’s happened to them —
“Why am I a fucking CAT?” a belligerent voice screams. Izuku dashes to the alleyway, and if the voice didn’t give it away, his nose is suddenly filled with a scent that is distinctly Kacchan — caramel and hickory smoke. He can also detect a note of panic in Kacchan’s scent. As he mumbles to himself about the scent glands of a cat and how powerful they must be, he comes across Kacchan crouching in a classic cat panic position. And oh — Kacchan looks cute. He is the fluffiest beige Persian with a squished nose and wide red eyes. His tail is bottle brushed and standing at attention. He draws his gums back and shows Izuku his canine teeth.
“Kacchan - it’s me!” Izuku says soothingly.
“I know it’s you, shitty Deku. You look like a nerd even in cat form.”
“Kacchan...”
“Plus, I can SMELL you. And why do you smell happy, you damn nerd?”
“I-I’m not happy.” Izuku lies. “I’m just relieved to have found Kacchan so quickly!”
“Sure.” Katsuki sneers. “Now, what the hell happened to us?”
“It was a villain! I didn’t recognize her, but she had a cat head and a woman’s body.” Izuku shivers as much as a cat can shiver. “She purred in my ear and tapped me on the shoulder, but by the time I called out, I blacked out and woke up here, same as you.”
“Tch.” Katsuki sounds annoyed. Izuku watches him experimentally try to activate his quirk, but no luck. Izuku knew it wouldn’t work because he had already tried! At least they can see well in the dark, it seems. He glances at his own fur but can’t tell if he’s green. He looks like he’s maybe a muted grey but not sure. The colours around him seem dulled down, although Katsuki’s eyes still pop with ruby hues.
“Let’s go home and tell our parents what’s happened!” Izuku suggests, and Katsuki agrees since they don’t have much choice.
“I texted All Might before it happened and started calling 110. Maybe the call went through, and they can trace it?”
“Not sure, Kacchan. They took your phone anyway, and nobody was around. We had better get going.” Izuku knows that he has released a tiny bit of fear scent but tries to be brave and starts leading Katsuki out of the alley. As the first one to be hit with the quirk, he feels somehow responsible for Kacchan.
“Don’t try to speed ahead of me, nerd.” Katsuki sneers from behind him and dashes ahead of Izuku, tail dancing in the air. Izuku sees fresh snow sticking to Katsuki’s fur and can’t help but giggle.
“Kacchan... this may sound weird, but I think I can smell my home.” Izuku raises a delicate paw and sniffs at the air. He smells a comforting herbal smell and katsudon cooking. “Can you?”
“What the hell, nerd — wait. Yeah. I smell soap and fireworks. That’s the hag and the old man!”
“Let’s follow the smells, Kacchan!” Izuku says excitedly, and the two start running down the street together, leaving paw prints in the snow.
They pass some shops with western-style Christmas lights and pass by the KFC where happy couples are grabbing their Christmas buckets of chicken. Izuku’s stomach growls, and his pupils dilate.
“I’m hungry, Kacchan.” he whines.
“Me too, nerd. Maybe we can get something to eat, somehow?” Katsuki suggests that the two of them temporarily forget their mission of getting home.
They see a young couple leave the store with smiles.
“Oi!” Katsuki yells at them. “Give us some chicken!”
The little woman giggles and covers her mouth with her hand.
“Oh, look at the precious kitties!” she coos to her partner, holding a gigantic bucket of chicken.
“Oi! Space cadet! I said pass me some chicken.” Katsuki growls.
“Ah! You’re so cute! Did you hear that cute meowing! He almost sounds demanding!” She laughs softly and grabs two chicken drumsticks from the other’s bucket.
“Y-you can’t understand us?” Izuku gapes.
“Aw; the green one is so tiny and cute. I wonder who dyed your fur green, though. Kinda mean.” she says thoughtfully, placing the chicken on the ground.
Katsuki and Izuku leap for the chicken, completely demolishing it. Izuku wipes his mouth with his paw but finds the KFC owner standing outside the store and glaring at him.
“Shoo! Get away from my store!” he yells at them, waving a broom, and Katsuki suddenly hisses loudly, baring his teeth. Katsuki and Deku stare at each other in shock at the hiss, then take off.
“Bye, cute kitties!” yells the young woman who gave them the chicken.
“So, humans can’t understand us.” Deku mumbles. “Our speech just sounds like meowing to them.”
“No shit, nerd.” Katsuki gruffs, trying to shake the snow from one of his fluffy paws. It’s stuck between his jellybean-looking toe things, and it’s damn cold! He bites at it with sharp teeth and glares at Deku. This is all the nerd’s fault. Probably.
“Okay... we will have to communicate with our parents another way. Did you hear the girl say that I’m green?” Deku asks. “Maybe that will give them a clue.”
“Let’s go, nerd.” Katsuki says. They can smell threatening smells from nearby alleys and don’t want to run across anything nefarious in this form. They couldn’t very well fight a villain like this.
Katsuki sniffs the air and says, “Follow me!” He and Izuku start padding quickly through the increasing snow drifts.
“It’s c-cold out here, Kacchan.” Izuku chatters. He isn’t as fluffy as Kacchan and feels the cold wind quite harshly.
“Just keep up, nerd.” Katsuki keeps up a good pace, lifting his fluffy paws carefully as he walks.
Izuku sees a doorway leading to an apartment building slightly open. He’s shivering quite a bit now and doesn’t think he can walk any further. His paw pads are freezing and getting painful. Before he knows what he’s doing, he squeezes into the door crack, seeking warmth.
“Deku!” screams Katsuki behind him. “What the hell are you doing, idiot?”
“I’m freezing, Kacchan!”
He hears Katsuki curse behind him but rushes into the warmth of the lobby. He curls up into a small ball of green fluff in the corner, trying to avoid the security camera overhead.
“Deku, what the hell? We have to go home.” Katsuki has followed him into the lobby angrily.
“It’s warm here, Kacchan.” Izuku whines, shivering.
“Well, yeah, but we have to suck it up and get out of here. What if someone calls animal control?”
“Just g-give me a few minutes.” Izuku feels stressed and has a sudden strange urge to lick his fur. He tentatively gives it a try and somehow finds it soothing.
“What are you doing?” Katsuki asks, scrunching up his smooshed nose even further.
“Feels good.” Izuku says, feeling calmer. He begins licking and biting at his own cold feet, then stretches out a leg and gives it a tentative lick.
“You’re doing it wrong.” Katsuki says, stepping closer.
“Huh?” Izuku looks up at Katsuki, who is now looming over him, twitching his tail.
Katsuki squishes against him and starts aggressively licking his face.
“Ah! Kacchan! What are you doing?” Izuku squeaks.
“Ugh- I don’t know. You’re just — doing it wrong. I’m supposed to do that.” he grumps and continues licking Izuku’s head and face with his sandpaper tongue.
“Kacchan! That’s embarrassing.” Izuku knew if he were in human form, he would be beet red right now.
“Oh yeah? Then why are you purring?” Katsuki asks between licks.
“I’m not!” Izuku shrieks, then bites Katsuki's neck.
“Ow! What the — “ Katsuki is about to yell, but a person enters the lobby where they are crouched in the corner.
“Oh my!” she says; it’s an elderly woman. “You poor dears must be trying to get away from the cold! Let me take you upstairs with me for the night!” With that, she reaches down to Izuku and picks him up. He stares at Katsuki with big eyes.
“Kacchan; help me!” he pleads.
“My, do you do a lot of yowling!” The old lady grins. She then reaches down with her other arm and scoops up Katsuki, who wriggles and squawks in protest.
“Be careful, kitties!” she admonishes. “Let’s go upstairs for the night! It’s too cold out there for cats tonight.”
Katsuki and Izuku stare at each other in dismay.
“We have to go to our parents’ place! What if we stay like this?” Izuku cries.
“I know, you damn nerd. Let me think.”
The old lady pets Katsuki behind his ears, and he can’t help but let out a little purr. Izuku giggles, and Katsuki glares at him, whiskers twitching.
They enter the old lady’s apartment. “It smells weird here,” Izuku says, sniffing around at the furniture.
“It smells like old lady, you damn nerd.” Katsuki grumps and jumps on the coffee table, experimentally knocking a pencil to the floor. The old lady chuckles and ruffles Katsuki’s fur. Katsuki lets out a little hiss, and Izuku giggles.
There’s a space heater on the floor and Izuku curls beside it. It’s so warm and cozy that he can’t help but drift off into a peaceful slumber.
He wakes up later to the smell of tuna! Kacchan is eating out of a can placed on the floor. “Give me some, Kacchan,” he whines, and Katsuki laughs, swatting at him. Izuku shoves his muzzle beside Katsuki and starts eating. “You poor dears, you must be starving!” The old lady coos.
With that, she puts on the news. “Look at this story — local woman selling rare exotic felines for thousands. Good thing she can’t find you; with your green fur.” She says, leaning over to ruffle Deku’s fur. He purrs despite himself.
Katsuki looks at the tv and lets out a little hiss. “Isn’t that the villain you were talking about, Deku?”
Izuku stops eating tuna and looks over at the tv. His eyes widen when he sees the villain that turned them into cats. “It’s her!” he shrieks. On TV is a voluptuous female in a shiny gold lamé dress and gold platform heels, with the head of a Siamese cat. Both boys shiver as the effect is quite off-putting.
“Deku, look. Doesn’t that cat she’s holding look like Round Face?” The villain is tightly holding a small brown cat with two circular pink markings on its face. She’s telling the host how rare this particular cat’s markings are and how it’s precious. She says she will be having an auction very soon with her collection of exotic cats.
“Kacchan! We have to do something!” Izuku yowls, feeling concerned.
“We’re cats, dumb ass! What the hell can we do about it?”
“My, you two sure meow a lot.” smiles the old lady.
After the brief about the exotic cat auction, the next segment is about missing UA students. As the newscaster rhymes off a list of missing students who never made it home for the holidays, Katsuki and Izuku are stunned to hear their names, along with Todoroki, Kaminari, Uraraka and Tsuya. They look at each other in dismay.
“Our moms are going to freak out.” whines Izuku.
“Tch. Maybe yours will. Mine knows I’m a badass.” Katsuki says, half-heartedly batting at a cotton ball he finds lying on the floor.
Izuku stares down at the ball. “Let me try, Kacchan,” he says with a competitive edge to his voice.
“Screw you, Deku, find your own damn ball.” Katsuki growls and bats the cotton ball out of the way. Izuku pounces like the nerd that he is, and the next thing they know, they are hissing and spitting at each other, and their fur is flying.
“Kitties! Please!” the old woman pleads. “Don’t fight, or I will have to let you go.”
The cotton ball temporarily forgotten, the two of them glance at each other and nod slightly. They get into a rowdy fight, with lots of scratching, hissing and yowling. Katsuki knocks over a Hummel ornament for good measure.
“That does it, I’m sorry, but you kitties will have to go!” the old lady says. “I can’t have you destroying my apartment!”
She carries them down to the lobby under each arm. Katsuki gives out the odd hiss at Deku to reinforce the situation, and Deku kicks wildly in the old lady’s arms.
“My, you are feisty kitties.” she admonishes. “Now be careful out there,” she adds as she opens the lobby door and releases them into the snowy night. They rush into the snow, Izuku racing close to Katsuki to absorb some of the heat that seems to radiate even in cat form. They slip through the shadows and make it to the Bakugou residence. They both howl and scratch at the door, Katsuki feeling an extra thrill at dragging his claws down the front door and seeing the paint scratch.
“What the hell is going on out there?” demands Katsuki’s mother as she flings the door open. She looks down at the two snow-covered and shivering cats and says, “Oh, shit.”
“Masaru! Inko! The boys are back! Well — kind of.” Mitsuki calls, peering down at them and cackling. “Katsuki, you still look like a brat even in cat form!” Katsuki hisses at her, and she laughs.
“Oh my poor baby! Oh Izuku!” cries Izuku’s mother, picking him up and clutching him to her chest. He stares at Katsuki with wide eyes as Katsuki’s father gently picks up the sopping wet and miserable Persian. The two carry the cats to the bathroom, where Masaru starts gently blowing them dry with a hair dryer. Izuku swoons under the warm heat, while Katsuki looks furious as his fur poofs out from his body in all directions.
“Honey, can you understand me?” Inko Midoriya asks, staring into Izuku’s green eyes. Izuku tries to nod as best as he can as fat tears flow down his mother’s cheeks. “Who did this to you?” she cries.
“We need her to call All Might and Aizawa.” Katsuki says and Izuku nods. “I have an idea.” The parents look down at them in awe as they hold a conversation in what sounds like meows.
Izuku wiggles wildly from his mother’s arms until she places his green form on the ground. He takes several leaps to his room and springs into the bed, where he finds a small All Might plush and drags it back to the bathroom. Masaru puts Katsuki down, and the two shout (yowl) and paw at the plush, looking expectantly at their parents.
“You want us to call All Might?” They both repeatedly meow until his mother goes to make the call.
She talks rapidly to the retired hero and explains that the boys are home, in cat form. All Might informs her that they know who the villain is, and she has several students from different schools in her clutches, turned into exotic cats. They will have an early morning raid, and after that, they will bring the boys and all the others to the prison, where the villain will reverse their quirk.
They need to just hang tough for the night, and Inko starts to stand up to get ready to leave with Cat-Izuku.
Izuku gets nervous and looks at Kacchan, curled up on the kotatsu. Red eyes look back at him, and a fluffy beige tail swings back and forth. Before Izuku knows what he’s doing, he hops onto the warm table and curls against Kacchan. Kacchan will probably kill him when he returns to human form, but for now, Izuku will chase the warmth.
“Looks like we can’t separate the brats right now!” laughs Mitsuki. “Let me set you up in the guest room.” Inko looks worriedly at Izuku. Izuku, who right now is curled up next to Katsuki and purring while Katsuki grooms him, giving gentle licks to his ears, top of his head and back of his neck. Izuku purrs and half closes his eyes.
“Kacchaaan.” Izuku quietly whines.
“What is it, you damn nerd?” huffs Katsuki, dragging his sandpaper tongue right down the front of Izuku’s face.
Izuku sighs. Why is he letting Katsuki groom him anyway? Somehow it seems right. Like Kacchan is in charge. Which doesn’t feel right. Ahhh! It’s as if his human and cat sides are battling for control, and both are losing. He feels like giving Kacchan a little bite, just for existing, so he does. Katsuki yelps and then narrows his eyes.
“You damn Deku!” he yowls and hisses, and his mother throws the door open. “Katsuki! Shut the hell up!” she snarls into the room and then shuts the door again.
“Hmph.” Izuku says and curls up once more around Katsuki. “Kacchan is soft,” he whispers, and he can feel himself purring against Katsuki’s fluffy beige body.
“Shitty nerd.” Katsuki rubs his cheeks all over Izuku.
“Eep- What are you doing, Kacchan?” Izuku squeaks.
“I dunno — I guess — marking you.” At Izuku’s wide eyes and gasp, he spits, “Shut up, you damn nerd! I can’t help it.”
Izuku giggles and lets it happen. It feels safe and warm with Katsuki. They will deal with whatever this is once they are safe and human again.
The next morning, the boys wake up, taking long spine-tingling stretches. To their mortification, someone has set up a litter box, but they both run to the bathroom and perch on the toilet instead. Katsuki jumps on his mother’s kitchen table because he can, and she swats him away. Inko and Mitsuki make some eggs with hot sauce for Katsuki, although he doesn’t seem to have the same taste in this form.
They wait patiently until they get the all-clear from All Might. Aizawa and Shinsou worked together to capture the villain and force her to turn the cats she had captured back into the missing students.
“Damn freak.” mutters Katsuki about Shinsou, but not without a bit of respect.
“Time to go to jail, brats!” cackles Mitsuki. “Do we need to put you two in a crate, or can you behave?”
Katsuki hisses at her in response, and Izuku looks up at his mother with big green eyes. She picks up his lithe, green, speckled form and cuddles him. Izuku purrs and snuggles against his mom.
Masaru picks up Katsuki, who struggles a bit, fussing, “I can walk, old man!” but it only sounds like hissing and the adults all laugh.
“He looks the same as a cat.” Inko laughs. “And so does my Izuku. Amazing how they still have their original essence.”
“I do NOT look the same.” Katsuki frowns, and Izuku looks over at him. His beige fur is fluffed around his face, and his red eyes are narrowed into triangles which usually would be intimidating but are adorable in his squished Persian face.
“Kacchan looks cute.” Izuku says without thinking, and it just causes Katsuki to thrash about in his father’s arms, meowing angrily. Masaru makes soothing sounds and scratches behind his ears, calming him down.
Mitsuki drives like her usual manic self, and they arrive at the jail in no time. After going through security, they are led to a room with Eraserhead and Shinsou, and the villain is slumped in a chair, slowly licking her human hand. The parents drop the boys on the large metal table in front of the villain. Katsuki hisses and swipes at her, and Izuku forms a defensive pose, tail pointed in the air and fur on edge.
Before anything can happen, both Aizawa and Shinsou lose control and rush toward the table.
“Oh my God, they are the cutest yet!” Shinsou announces, picking up Izuku and cuddling him. Izuku giggles and doesn’t mind the attention, but Katsuki glares at Shinsou. “Tell that purple muppet to get his hands off you!”
“Why, Kacchan? It’s funny seeing this side of him.”
Katsuki lets out a little hiss, and Aizawa chuckles and scratches him behind his ears. “Maybe we should just adopt them instead. They are probably less trouble in this form.”
“These two are clever.” The villain hisses, narrowing her ice blue eyes at them. “The others were frozen in shock, but these two ran into an alley. Someone was coming so I had to leave and couldn’t search for them. Too bad, they would have fetched a pretty penny.”
Katsuki says, “Shut up, you damn cat head. Change us back.”
She smirks. “I don’t have much of choice, do I?”
Izuku mutters that she can understand humans and cats, but before he can go off on a tangent, Shinsou asks her a simple question, to which she responds, knowing that she has no other options.
She taps first Katsuki, then Izuku on their shoulders, and they return to human form, sprawled in a heap on top of the cold table.
“Ugh! What the hell.” Katsuki jumps off the table in a single leap and glares at the villain and everyone in the room.
“Ah! We are still wearing our clothes!” Izuku says, fascinated. “I guess they transmogrified with us!”
“Oi, stop muttering.” Katsuki fusses. “And stop freaking staring at us, you weirdos!” he yells to everyone else in the room.
“You were better as a cat.” Shinsou smirks.
***
Later that night, there is a little party at the Bakugou house to celebrate all cat-kids returning to human form. Katsuki and Izuku hang out with their respective squads, but glance at each other from time to time through the course of the evening, Izuku from his centre of the circle where he holds court with the nerds, and Katsuki from the couch where he is slumped between Kaminari and Kirishima who both have their arms around him and coo over the pictures of him in cat form that his mother screencasts over the big tv.
As the party winds to a close, Izuku returns to the guest room in the Bakugou house. All the classmates are sleeping over, crashing on the couch, under the kotatsu and on the floor. The Midoriyas get their own rooms as slightly privileged guests. After brushing his teeth and washing up, he tries to sleep, but something is off. The bed feels lonely and cold, and he thinks back to the day before, curling around Kacchan’s cat-form until he fell asleep. He sighs and tries to get comfortable.
He lies in bed staring at the ceiling for a good while until there is a loud and unpleasant knock on the door.
“Ah!” he startles and walks to the door. “Who is it?”
“Oi, let me in, you damn nerd.” gruffs Katsuki from outside the door. Izuku’s heart warms when he hears Kacchan’s voice, and he lets him in immediately.
“H-hi Kacchan.. what are you—“
Without a word, Katsuki flops onto Izuku’s bed.
“Um, oh, okay, this is happening...” Izuku mutters, flushing a deep red.
“Shut up, shitty Deku, I can’t sleep; if I don’t get my 8 hours, I will be very pissed off at you.”
“So what’s new about that?” Izuku mutters and then loudly says, “What am I supposed to do about it, Kacchan?”
“Get over here, dumb ass.” Katsuki grunts, and Izuku tentatively approaches the bed as if he is about to defuse a bomb.
“Just lie here and shut up.” Katsuki barks, and Izuku giggles. “I didn’t say anything, Kacchan.”
He crawls into his bed, and the two lie stiffly and awkwardly next to each other. But before Izuku knows it, a warm Kacchan has wrapped himself around Izuku and pulls him in tightly.
Izuku lets out a small “meep!” and Katsuku mumbles into his green curls, “Shut it. It’s just to help me sleep.”
Izuku giggles and snuggles into the warm body. “I know, Kacchan. I liked cuddling with Kacchan last night when we were cats, too.”
“Agh! Shut up, you damn nerd! Never say cuddling again!” Katsuki yells but doesn’t release his tight grip on Izuku. Izuku happily drifts off and swears he can feel Katsuki purring somehow.
And nobody needs to know if they need to not-cuddle to sleep every night in the dorms when they return to school. (Even though all those extras know anyway. And none of them are in the least bit surprised.)