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Katsuki was a cat.
Actually, it was probably more accurate to say that he was a kitten. He just woke up like that, tangled up and confused in his sleep clothes. When he finally detangled himself, he found that he was still in his dorm room bed and everything else looked normal. He was just very tiny.
And fluffy. So, so fluffy.
Yesterday during patrol on their internship, Katsuki and Izuku had a run-in with an odd villain– dressed up fully like a black cat like the catwoman from the old movies that Izuku liked. She activated some kind of pink puffy smoke at them, but both of them got checked out later by the quirk doctor who cleared them, saying it must have been nothing.
But now that Katsuki was sitting here, full blond fluffy kitten, he was starting to think they’d been wrong about that.
Now the question was what to do about it.
Katsuki yawned big and stretched out in the bed, kneading a bit as he did so. He found himself cleaning the fluff around his neck with his tongue and stopped suddenly, embarrassed at the odd impulse. Peaking over the edge of the bed, he tried to figure out how to get down. Really, it was a long way for a tiny kitten, but he was a big and strong tiny baby kitten, so it would be no problem for him! Katsuki jumped, landing his paws, but didn’t quite have the strength to land gracefully as he crashed to the floor.
“Ow!” Katsuki complained, though his voice sounded very weird, making more of a ‘mrow’ sound than anything else. He shook it off and made his way to the door to escape. After all, he would need to find someone who could help him, probably Mr. Aizawa or All Might. But… the door was so big and the door handle was way up high. There was no way he could reach that from way down here!
While he thought, Katsuki sat back on his rear and curled his tiny tail around his body. Hmm… oh that’s it! There was a desk chair and the desk right next to the door. He had to run and jump, clinging on with sharp claws to get to the chair, then the desk was just a hop away. From there, he jumped off, aiming for the door handle. He got it, just enough to jiggle it open, but then it was a long way down for a little kitten. Crashing again, this time with a little roll, Katsuki struggled to right himself for a minute before taking off through the open doorway before it could close.
He’d only been a kitten for a few minutes, but so far had not liked any second of it. This was so annoying!! How was he supposed to do anything as a kitten? Fuck that catwoman for doing this to him! When he got his hands on her, she was gonna pay!!
Katsuki made his way to the staircase to go down, but every step was so big that he flubbed every one of them, landing on his butt or tumbling in a roll. It was a long way down. Eventually he got to the common area, hoping to find a teacher that could help.
But the only one there was Izuku.
Katsuki sighed. Well, this was better than finding no one. And he could tolerate Izuku a little bit better these days, he could admit that. They were better friends nowadays than they ever were. That still didn’t mean he was ready to admit he needed some help from the green haired bastard, though it looked like he had few other options.
“Hey! Deku! Damned nerd!” Katsuki yelled out from the floor, just in front of where Izuku was camped out on the couch. It looked like he was doing some school work.
“Oh! Ohhh my gosh, look at you!” Izuku cried, putting his pencil down to pick Katsuki up from off the ground.
Katsuki protested, loudly, as he squirmed in Izuku’s hands. “Hey! Don’t pick me up! It’s me, you moron!”
“Awww, so cute! I haven’t seen you around before, little guy. Are you one of Mr. Aizawa’s new cats?”
“What!!?” Katsuki hissed and thrashed in Izuku’s lap as the green haired boy held him. “Obviously not! It’s me! I’m not a cat, it’s me!”
“You’re little meows are so cute! I wonder what you’re trying to tell me…hmm… are you hungry, little guy?”
Fuck! Izuku couldn’t… understand him? Was he just saying ‘meows’? Great, just fucking great.
Clearly without knowing that he actually had a fearsome hero in his hands, Izuku scooped Katsuki up and held him to his chest and started to pet his fur. “It’s okay, little guy! Let’s go see what food we have for kittens.” Katsuki was jostled as Izuku moved him, but was pretty secured once he was held. He didn’t want to risk another crashing to the ground, so while he was so far up, he stayed put in Izuku’s arms. When they got to the kitchen, Izuku put him down on the counter top.
“No, no, not up here! Put me on the floor! I can’t–” Katsuki peeked over the edge. This countertop was really tall and the floor was hard tile. No way he was jumping down this way. He hissed again as Izuku rummaged through the cabinets and pulled out dry cat food. The green haired boy poured some out into a dish and offered it to Katsuki.
“Hssss!!” Katsuki raised his hackles and complained loudly. “I’m not eating cat food!”
“Oh, hmm,” Izuku pondered with a finger on his lips. “I wonder if you’re too young for dry cat food.”
“Fuck you! I’m not too young, I’m too human!”
He wanted to hiss at the next thing Izuku brought out, but it actually smelled really good. Katsuki snuck over with guarded steps to check it out.
“See? It’s tuna. Yummy!” Izuku smiled as he offered the bowl.
“Hmm. Well. Maybe… just a bite.” Katsuki sniffed it before trying some. Oh, yum!. It was super tasty. He tucked in, eating it up. There was a hand petting him in the meantime, and he found that he didn’t really mind that.
“Now, now, little kitty. You can’t eat all of it or you’ll get a stomachache!” Izuku said as he took the bowl away.
“Hey! I wasn't done!”
“I’ll give you some more at lunch, okay little kitten?” Izuku scooped him up again and brought him back to the couch. He held Katsuki in one hand as he packed up his school supplies. “Now, it’s time to go to class. Hm, but I bet Mr. Aizawa already left… You know what? Why don’t you just come with me? It’ll be fun little kitten!”
Katsuki had no choice as Izuku carried him with him. This was for the better anyway. He would have the chance to talk to others and someone could sort out his situation.
“Good morning, Mr. Aizawa!”
“Hello, problem child. What on Earth is in your hands?”
“A kitten, see?” Izuku held Katsuki up by his armpits, letting his tiny, fluffy belly hang down. “I thought it was your kitten, is it not?”
“Nope. Not mine. Where did you find it?”
“In the dorms, whoops. I wonder whose kitten I just took. Is it okay if I ask the class when everyone gets here?”
Mr. Aizawa nodded and gave Katsuki a little pat on the head. Izuku and him settled down in his seat, the green haired boy stroking his soft fur. It actually felt really nice and it made this vibrating start up in his chest.
“Aw, so cute,” Izuku murmured and got under his chin.
Class began and Izuku started it by holding him up again, asking who he belonged to. Katsuki tried to say again, loudly, that he belonged to no one and was himself. Everyone started saying how cute he was, how fluffy, and that he didn’t belong to any of them.
Except for the one with the weird shaped head. Koda. He ducked his head and giggled to himself, making everyone turn to look at him.
Katsuki quickly realized why– his quirk. That guy’s quirk was that he could talk to animals. He could hear him!
Except… Then there’d be a whole fiasco. They’d have to get Recovery Girl and some quirk expert. They’d probably have to call Endeavor since it happened to his intern. It would just be a whole thing.
Or… He could just wait to see if he got better soon. Maybe it wouldn’t last very long.
Koda opened his mouth, clearly about to say something, so Katsuki interrupted.
“Wait–” He sighed and fiddled in Izuku’s arms. “Don’t tell them. Uhhh not yet.”
“Okay!” Koda nodded in understanding. “Sorry, em, everyone. It’s nothing. Not my cat, but he’s sure cute.”
Katsuki bristled at this, but everyone agreed and moved on. Izuku held him in his arms all class, petting him and holding him close. Of course there was hubbub about where he was, Katsuki, the human student. Luckily, Koda seemed to understand enough and had the willpower to actually speak up for once to say, “Oh, he was feeling under the weather today and asked me to collect his school work for him later.”
Several classmates and Aizawa questioned why Koda of all people would be the classmate Katsuki would turn to, but in a quick discussion they all agreed that Katsuki probably tolerated the guy just fine because of how quiet he was. They were able to move on as Katsuki mewed a quick ‘thanks’ to the animal quirk guy, who smiled and waved at him.
He tried to pay attention in class, he honestly did. But the sun was streaming in the window, and Izuku’s lap was so warm. So he floated in and out of napping the whole day instead. It was so much nicer that way. Plus, he got scritches on the top of his head while he slept, and that made him happy inside.
During the breaks, Izuku shared him amongst the classmates, letting all of the girls ooh and ah over him. After Ponytail picked him up to ‘check if he was actually a boy cat’ he scratched her and they all left him alone for a bit. It was better in Izuku’s arms anyway.
“Oh! He needs a name!” Round Cheeks declared after helping Ponytail clean the scratch marks.
“I don’t need a name. I already have one,” Katsuki tried to tell them, but they all just reacted to ‘how cute his meows are’.
“Actually, I already thought of one,” Izuku interjected. The green haired boy had him flipped upside down belly up, and was playing with the soft fur on his underbelly. Katsuki was letting it happen, but if Izuku said a stupid name, he was gonna get clawed. “What about… ‘Cat-suki’?”
“Cat-ski? Like a cat skiing?”
“No, no!” Izuku laughed, “Like Katsuki! It’s just that… this little guy reminds me of Kacchan for some reason. I think it’s the fur. So, Catsuki!”
“Ohhhh!” The girls cooed.
Round Cheeks placed a bet and tried to pet Katsuki’s belly too, but he swiped at her to back off. “Aw, Catsuki is so cute!”
For lunch, as promised, Izuku got him more tuna fish. Katsuki tried to eat as much as he could before Izuku took it away. He was a growing kitten! He needed his nourishment.
After lunch, he was full of energy. Izuku let him run around the room a bit. A couple classmates made him makeshift toys to play with out of paper and paper clips. His favorite was a braided string that Izuku had Ponytail make for him. It was fun and easy to rip up.
Apparently he was being distracting, so Mr. Aizawa held him for a while to try to calm him down. He had been having fun playing, but whatever. It was also fun to climb around the capture weapon, too.
He was handed back to Izuku at the end of the day. By then he was worn out again and happy to sleep in the green haired boy’s arms. It was a sunny day, so they went outside to do school work. Well, Izuku did school work with his moron squad while Katsuki searched for butterflies to attack. Todoroki was the funnest to play with as he made little ice sparkles go off from his fingertips for Katsuki to chase. He ended up pouncing all over their school work, but no one complained.
Izuku brought him back to his room at the end of the day, placing him on Izuku’s bed while the green haired boy went to shower and get ready for bed. It had been a whole day and Katsuki was still… well, Catsuki, apparently. Maybe this was a 24 hour thing and he’d be human in the morning.
When Izuku was all ready and changed into pajamas, he hung out with Katsuki on the bed while he read with a flashlight.
He knew it! Katsuki knew Izuku stayed up too late, of course the boy was reading some hero comic book, it was just like him to do that.
“Hey, Deku!” Katsuki knew by now Izuku couldn’t understand him, but he could hear him at least. “Let’s go to bed, it’s way too late!”
“What’s that, little Catsuki? Should we go to sleep?”
Ohh maybe he can understand? Or it was just the obvious complaint to make. It was nearly ten pm! Time to be asleep hours ago!
Izuku shut off his flashlight and put down his book to snuggle in the bed with Katsuki. The little kitten tucked in, right underneath Izuku’s chin when the other boy lay on his side. Katsuki purred happily, enjoying the warmth of cuddling. Why didn’t they do this more often? It was nice! Especially when Izuku leaned down to leave a little kiss on the top of his fluffy head.
He fell asleep quickly, but his last thought was that of worry. If he did actually turn back to a human in the morning, wouldn’t he wake up naked, in Izuku’s bed!?
Oh well. That was something to figure out later.
_______
It turned out, Katsuki didn’t have anything to worry about. In the morning, he was in fact still a kitten.
But… so was Izuku.
There was a sleeping kitten right next to him in the bed when he woke up, snuggling with him and purring loudly. The kitten was dark with a hint of green in his fur. When he sniffed and opened sleepy, confused eyes, it was Izuku’s green eyes staring back at him.
“Whoa, what!”
Katsuki snorted and stretched out, letting his back arch to get out all the cramped spots. “Welcome to the cat world, Deku.”
Izuku sprang up, widened eyes looking around the bed frantically. “K-kacchan?!”
Katsuki rolled to his back, licking at a paw to bathe himself. “Don’t you mean… Cat-suki?”
“Oh! It’s you! Wait– oh no… it was the quirk, wasn’t it?”
“I assumed so. That damned catwoman.”
Sitting down and taking a sigh, Izuku started giggling, mewing like it was hilarious.
“What, Deku?”
“I can’t believe it’s you! Do you know how adorable you are as a kitten, Kacchan?”
“Ugh,” Katsuki puffed up, trying to look big and menacing, “How about now?!”
Izuku laughed so hard, he fell off the bed, crashing on the floor with an oof!
“Oh shit,” Katsuki cursed and jumped after him. He himself was starting to get a little better at the jumping part and landed with only a bit of a skid. “You okay?”
Jumping up on all fours with a determined look, Izuku nodded. “Just fine. But… now what?”
“Hmmm…why don’t I show you the ropes? How to be a cat.”
Izuku giggled again, pouncing up and down like he was too excited. “That sounds like fun! Let’s do it!”
Katsuki showed Izuku how to open the door, though it was easier with two of them since one could help keep the door open once the handle was jiggled. Of course Izuku was laughing the whole time like it was the greatest thing in the world. The stairs weren’t any easier than the day before, but Katsuki was pleased to see that Izuku had just as hard of a time as he had getting down each one. Eventually they made it to the common area, but no one else was awake yet.
They figured out together how to get into the fridge where Izuku had put the leftover tuna yesterday. They weren’t able to grab it or anything, so Katsuki just pawed at it until the bowl fell out of the fridge. Luckily the bowl didn’t break, but the tuna had splattered all over. Neither of the kittens minded, and just ate it all up.
Next they ran around the common room, finding odds and ends to play with. There were a few things under the couch– missing sock, balled up paper, a hair clip. The hair clip was fun because it made noise as Katsuki clattered it around on the floor. Izuku liked the sock because he could hold it with his front paws and bunny kick his legs to get at it. He looked quite ridiculous with his determined expression, so Katsuki tried to steal the sock from him, resulting in a full chase around the common room.
Eventually, they tired out. They helped each other climb up on the couch to find the good, soft blanket to lie down on. Katsuki wanted to nap for a bit, but after all that running around, both of them could use a good clean. It was hard as a kitten to get all of his spots, so he knew that Izuku would have the same problem.
As they curled in together on the blanket, Katsuki used his tongue to bathe Izuku’s fur, trying to get everywhere. Izuku did the same thing for him, especially around his face where on his own he could only get at with a paw. He felt his fur stick straight up on the top of his head where Izuku got at the fur there, the wetness stuck around for a bit. He purred against the other kitten though, and closed his eyes as Izuku worked on him. They curled around each other when they were all done, sharing body heat, and slept.
Their classmates came downstairs eventually and all gathered around the sleeping kittens. Katsuki heard Round Cheeks declare that the second kitty looked a lot like Izuku, and they all agreed. She even named him ‘Mew-doriya’ which Katsuki rolled his eyes at.
Someone brought them more tuna and someone else petted them with a very warm hand– Katsuki was pretty sure it was Todoroki. Ponytail made more cat toys for them to play with using her quirk and Mr. Aizawa talked to several classmates about proper care of kittens.
Eventually they were going to have to let Koda tell the teacher what was actually going on, but for now, they were just happy being cats.