Katsuki's not stupid.
He was the first kid at his school to learn how to read, after all, so he knows he's smart! Plus he can count all the way to one hundred, and he can get home from school all by himself, and he knows all the top heroes. He knows he's not stupid.
But lately, everything's been making him feel like he is.
Ever since Izuku got his quirk.
Since then, he's been acting... different.
At first Katsuki thought that maybe he'd been replaced or something, but there's no way the Deku from before was important enough for a villain to in-person-ate. Villains don't pretend to be quirkless nobodies.
And besides, Katsuki was there when it'd happened. He'd seen with his two own eyes the way Izuku... changed.
Any other kid woulda been scared seeing that, scared of having their quirk stolen and used against them. Scared of being made useless. But Katsuki definitely wasn't! He's too tough to be scared!
He's not scared, and he's not stupid.
And Izuku is still the same Izuku... kind of, only he's different now. Weird.
He still gets all mumble-y about quirks, and flinches at loud noises, and doesn't like to be touched. He still doesn't like uncooked broccoli cause it gets stuck in his teeth.
He still calls Katsuki 'Kacchan.'
But he does other stuff now too that the Izuku from before didn't do.
For starters, he acts totally different when the adults are around. Or, actually... he acts the same as before around them, but it was different, like he was playing pretend. Like he was pretending to be a kid, pretending to be like how he was before he got his quirk. And nobody else seemed to notice it but Katsuki.
Izuchan is different from Izuku, and way different from Deku.
Because a Deku is useless and weak—even though Katsuki's trying very hard not to think like that anymore—and the Izuku from before was way too nice for his own good.
Izuchan is different because he doesn't act like a Deku.
No, he acts like an adult.
The new Izuku uses big words that they haven't learned at school yet, and he doesn't fanboy over All Might anymore—which is weird because All Might is the best. He doesn't even care about playing games anymore either, instead just keeping to himself and always writing in his weird journal... though that part wasn't actually all that new, come to think of it. What was new was all the stuff he knows that he shouldn't know, only he was really good at hiding it. Izuchan was way better at hiding things than Deku was.
Then there was that creepy grin that's all teeth and meanness that Deku never used to do.
Any kid would be scared of a grin like that.
But not Katsuki.
Because Katsuki isn't scared of anything, especially not Izuku!
Sometimes Izuku got this super weird look in his eyes, too, like he wasn't really there. Like... his body is still there and everything, but in his head he thinks he's somewhere different; like he's not seeing Katsuki despite looking right at him.
That was kind of scary too, seeing Izuku not moving, barely even breathing, and the way he would react violently if anyone touched him when he was like that.
And Katsuki isn't stupid; he's known Izuku for their whole entire lives! So of course he notices this stuff.
He notices the way Izuku walks like a cat so he won't make any noise, when Deku was always super clumsy and tripped over himself a lot. Notices too the way Izuku is always watching all the doors and people, and the way he doesn't like it when there's anyone behind him that he can't see. Like he's afraid they're gonna suddenly attack him.
Which doesn't make sense, because Izuku totally kicked Katsuki's ass when he tried to do that—after he became different—so Katsuki doesn't know what he could be so afraid of.
At least that part was still the same, though; the way Izuchan and Deku both stuck up for the weaker extras. The way he acted like a hero—a real hero.
It still pissed Katsuki off, but unless he wanted to get his ass kicked again there wasn't much he could do about it. He just couldn't understand what changed that Izuku was suddenly able to take him down no problem when before it was always the other way around. It didn't made any sense.
All the new bruises on Izuku's skin don't make sense, either. The ones he was obviously trying to keep a secret from everybody, even from Katsuki. The bruises that looked like handprints.
They couldn't be from any of the other kids at school since Izuku is too strong to ever get hurt by extras like them, and cause Katsuki told them all to back off—though that was before they'd stopped listening to him, just because he'd started sticking up for the 'quirkless loser'... But he's still pretty sure it can't be from any of them. Like he said, they're just useless extras. Even with Isui Kano's little water show.
Katsuki is stronger than all of them, and since Izuku had changed he'd become leaps and bounds stronger than Katsuki, so it can't be any of their stupid classmates. The two of them were both gonna be heroes unlike everybody else here, Katsuki knows that for certain.
Another thing he knows is that the bruises aren't from him—not anymore.
But Izuku is still getting hurt.
And he still wasn't telling Katsuki about it.
It's annoying as hell, makes his chest feel all hot and tight. He hates being looked down on like that; like Izuku doesn't think of him as a good enough rival, like he's no different from all the other extras.
Like somehow, in just the blink of an eye, Izuku had left Katsuki behind and become a hero without him.
But that just means Katsuki has to work harder to catch up, and that started with figuring out why Izuku was acting so weird and so different in the first place.
Katsuki knew it was more than just him getting his quirk.
Another one of the things he'd noticed was how different Izuku has been acting around his mom—around Auntie Inko. Like he didn't wanna be near her anymore. He acted like that sometimes before too, but now it was all the time; the way he would go all stiff whenever Auntie Inko got near him or touched him. Especially when she touched him.
But Izuku would never say anything to make Auntie Inko stop, either.
And there's nothing Katsuki can do about it, because Izuku didn't seem to care and Katsuki can't think of the right words to ask.
It was mostly just little bruises anyways, tiny things that Katsuki only really sees when Izuku's shirt would lift or when his sleeves sit weird. It's never anything big enough for the adults to notice.
Until today.
On the Monday after stupid Isui Kano decided to try and drown Izuku, Katsuki gets there early and has to sit at his desk waiting for Izuku to finally arrive. Then when he finally does, Katsuki rushes over to greet him.
Only he doesn't make it all the way there before he sees the bruises on Izuku's face.
He had a big white patch over his right eye, but some of the bruising—dark purples and greens that make Katsuki's stomach twist—were still peeking out from under the edges. He could see lots of other bruises on Izuku's arms and neck, too.
"The hell happened to you?" he has to ask.
And Izuku's answer is just—it's weird.
"I punched myself in the face," he says in that low, drawling mon-o-tone that he also never used to do, and Katsuki's face scrunches up, because, why would he punch himself in the face? That didn't make any sense! But before Katsuki can say anything about it Izuku's already adding, "Just kidding. I got beat up on Saturday."
Which made EVEN LESS SENSE!
"You got beat up?" Katsuki echoes dumbly—all wrong, he's supposed to be smart. "How?"
But Izuku just shrugs.
And it just—it doesn't make any sense. Because Izuku is strong, stronger than Katsuki—as much as he hate, hate, hates to admit it—and Katsuki can't figure out who the hell hurt his friend.
But Izuku isn't even looking at him anymore, and when Katsuki turns to see what he is looking at he sees...
Isui Kano?
Fucking Isui?
He notices that Isui looks angry, glaring lots at Izuku, which is dumb because he's not the one that got sent to the principal's office last week. The principal hadn't even called his mom to the school, even if Katsuki's mom put him in his place anyways.
So what could he be so angry about? And what did that have to do with Izuku's bruises?
"Hey, don't worry about it," Katsuki hears Izuku say. "The bruises will probably all be gone by next week. I've had worse." And Katsuki whirls around to face him, trying not to flinch, because he knows Izuku's had worse; he's the reason Izuku's had worse. And he knows, now, that the new, stronger Izuku could make him hurt just as bad, but it doesn't hurt at all when Izuku nudges him to move away from the doorway.
"Come on," he says, "Let's go take our seats before Tanaka-sensei gets here."
And that's why Izuchan is so weird, because Deku would've been flinching and stumbling over his words and a-pol-o-gizing lots, but he wasn't doing that right now because no adults were watching.
Until Miss Tanaka enters the room and Katsuki can almost see the shift where Izuku holds himself different, ducking his head and lowering his shoulders so he looks smaller; back to acting like his 'normal' self. His old self. Back to acting like a Deku.
Izuku was Deku, and Izuku is Izuchan, but Izuchan isn't Deku.
And Katsuki isn't stupid.
Izuchan doesn't pretend as much around Katsuki, but he still pretended a little bit.
So Katsuki decides that figuring out what's wrong with Izuku and what stupid extra Isui has to do with it is more important than paying attention to today's lessons. He already knew most of this stuff anyways.
Except he gets kinda distracted right away by Izuku's new family name. Because Izuku's been a Midoriya for their whole lives; Katsuki didn't even know a person's name could suddenly change like that! Does that mean his family name could change, too? Could he stop being a Bakugou?
But his mom and dad are still together, unlike Izuku's, so probably not.
He'll have to ask once he gets home though, just to be sure.
Anyway, he's getting sidetracked, because Isui is acting super weird today today, too.
He kept trying to corner Izuku, and Katsuki could tell Izuku didn't want to talk to him because he kept making it super difficult for Isui to corner him.
Since Izuku obviously doesn't wanna talk to Isui, Katsuki makes sure to stick close and glare right back at Isui to let him know he's not welcome! Because Katsuki and Izuku are in this together, and annoying extras can fuck off.
Only Isui is dumb, dumb, dumb, because he just doesn't take the hint.
It's not until the end of the day that Katsuki slips up. Some of the other kids come up and ask if he wants to play after school, distracting him, and he loses sight of Isui and Izuku. By the time he's said no and gotten his outside shoes on, they're gone.
Until Katsuki rushes outside and finds them both.
"Anyways, I don't see why you expect me to care," he hears Izuku saying, and he sounded... cold. Stand-off-ish. Scary. "Your brother and his friends literally held me down and attacked me."
They did what?
Katsuki could see them now, Isui all puffed up and Izuku standing too still.
Isui's mouth twists, hands clenched like they were on Friday, before he tried to drown Izuku. "Because—"
"Hey!" Katsuki shouts, rushing over so he can shove himself between them—so he can get Isui away from Izuku. He doesn't like the way Isui was trying to make himself look big, doesn't like the how he's looking down on them, doesn't like what he'd heard.
He doesn't like that he's got no clue what's going on, and he wants to know right the fuck now.
But he doesn't want to hear it from Isui.
So, Katsuki turns to Izuku and says, "Izuchan, I wanna go to the park. Let's play."
"We're in the middle of something here!" Isui protests. Katsuki squeezes his hands into fists and doesn't even look at him. He doesn't want stupid Isui there when he talks to Izuku; what he thinks doesn't matter.
"Don't care," he says, itching to just get out of here already. "Come on, Izuchan. Let's go play."
But for some reason... Izuku just smiles at him. Not one of his big smiles like from before or the shaky one like when he's nervous, but something smaller that feels almost... sad.
Katsuki doesn't like that, either.
"Sorry, Kacchan," he says. "I can't play today—or for a while, actually. I'm grounded."
Suddenly it feels like the ground's fallen out from under Katsuki's feet. It just doesn't make sense, because... grounded? Izuku never got grounded, he was too much of a goody two shoes.
Or, he was, before he started being weird.
"Grounded? You're...?"
"Yeah."
Izuku's smile gets a little smaller, a little sadder, as he says, "I gotta go home now, sorry." And then his smile disappears altogether when he looks at Isui, adding, "As for you, Isui-kun... If you know what's good for you, you'll leave me alone."
He turns away from both of them then, only offering a wave over his shoulder as he says, "I'll see you here tomorrow, Kacchan. Bye."
And then he just... walks away. He doesn't even look back.
Katsuki stares until Izuku's disappeared around the corner, mind racing.
Izuku got beat up by someone on Saturday. He spent the whole day today avoiding Isui. His mom grounded him.
Together, none of it makes sense.
It doesn't. Make. Sense.
His chest feels too cold, something ugly wriggling in his stomach, and he doesn't know how to make the world start making sense again.
Distantly, Katsuki hears Isui mutter, "Stupid Midoriya," arms crossed as he scuffs his shoe on the ground. "This's all his fault anyways. Why'd he hafta go and break nii-san's nose? Shoulda just sat there and taken it like he was supposed to..."
He keeps muttering, but Katsuki doesn't hear it.
Katsuki's not stupid.
So he turns and throws a punch right at Isui Kano's stupid face.
He's aiming to give him a black eye to match Izuku's, but he misses and nails him right in the nose instead. It doesn't matter either way, since Isui falls backward and immediately starts crying, blood gushing from his nostrils.
And as he jumps on top of Isui to punch him again, knuckles smearing with red, Katsuki feels the coldness in his chest be replaced by a more welcome burning.
No one's allowed to fight Izuku but him. Isui should know that by now.
Besides, it's not picking on someone weaker if they hurt someone else first... right?
Right, Katsuki's just getting back at a villain.
