Work Text:
Kirishima is the only one Bakugo allows to train with him. His hardened skin is perfect for blocking Bakugo’s explosions, which allows Bakugo to never really hold back. He hits Kirishima with all he has almost every day, and Kirishima really doesn’t have much to fall back on by way of attacking, so most of the time he just tanks the damage and moves on.
“I’ve got a new move I want to try out on you,” Bakugo had said, this morning, grinning madly, like usual. “So let me hit you with it.” Kirishima nodded, because this is really nothing new, and readied himself in the center of the training room.
His Hardening cut along his body, creating those jagged peaks of skin over his arms and legs.
“Ready!” he called, dropping into a stance designed to brace him against the floor. Bakugo grinned and launched himself into the air with sporadic little blasts. Then, he held out one of his hands as he was falling, and let loose one massive explosion. The room was bathed in bright light and a sound akin to fireworks drowned out all other noise.
Kirishima comes to on the floor, head spinning, Hardening completely melted away.
“That was awesome!” Bakugo cheers, walking- more like jumping, with how excited he is- towards Kirishima. “Even managed to knock you over with no buildup at all!” He offers a hand to Kirishima, which he dazedly takes, and hauls him to his feet.
“It’s a good one,” Kirishima agrees, putting a hand to the back of his head. It hurts in a distinctly different way to a headache or migraine. Something duller. It feels almost like he’s being repeatedly hit, rather than the sharp and regular pain of anything else. It’s never really felt this way before.
The way the room spins as he’s all but lifted onto his feet causes nausea to rise in his throat. He only barely manages to swallow back the bile before it reaches his mouth, but he brings a hand to his stomach anyway.
“Got me good,” he murmurs, trying very hard to steady himself and not throw up.
“See, that’s why you’re perfect,” says Bakugo, releasing Kirishima, thus removing whatever support he’d been giving. Kirishima sways. “I can hit you as hard as I want and it doesn’t hurt you.” Then why does it hurt so bad? “It’s kinda tiring though. My arms are a little sore.”
“We should stop for today.” Kirishima wobbles towards the locker room doors. “Get to- class, and stuff.” There’s something very wrong with his head, of that he’s sure.
“I can keep going!” Bakugo balks. “Don’t be a baby, Kirishima, we can still train!”
“No.” The locker room is so much further away than he remembers, why does it seem to keep moving away from him? “No, I think we should be done.”
“Hey! Don’t walk away from me, shitty hair!” Bakugo shouts. Kirishima can hear him stomping closer. “What, are you mad I managed to get you or something? Answer me!” Kirishima’s tongue has become lead, and before he can even think to try and stop himself, bile is rushing up his throat and out his mouth. “Kirishima?”
“Think we should- stop.” He falls. Bakugo stands behind him, hand outstretched, absolutely stunned.
“Kirishima?” he asks again, trying not to let his voice shake like it so badly wants to. “Man, that’s not funny, get up.” Kirishima doesn’t respond. Bakugo behaves as though he’s approaching a wild animal as he steps closer. “Hey, do I need to get Aizawa or something?”
But Kirishima doesn’t answer him. He kneels beside his friend, lifting him by the shoulder and rolling him onto his back. His eyes are open, but they’re half lidded and dazed. He doesn’t respond to anything Bakugo does to him, tapping his face, shaking his shoulders, screaming at him.
“Ok, ok, just stay here while I get Aizawa,” Bakugo says, stumbling to his feet and bolting towards the locker rooms where his phone is stashed. Putting his code into his locker is way too difficult with his shaking fingers, and takes him way too long, but he does eventually manage it. He has his teacher’s number as the first contact in his phone, and he fumbles to click on it as he rushes back out to his friend.
Aizawa picks up after only a couple of rings. “Bakugo, did you mean to call me? Aren’t you and Kirishima training right now?”
“Uh, yeah, but I need you to come down here.” His voice decidedly does not shake. “Something’s wrong with Kirishima.”
“What’s wrong with him?” Aizawa asks. Through the phone Bakugo can hear shuffling. “I’m on my way right now, but you need to tell me what happened. Should I call Recovery Girl?”
“I don’t- I don’t know,” Bakugo replies, sitting back beside Kirishima. “I’m back, and I’ve got Aizawa on the phone.” Kirishima still doesn’t react beyond a slow blink and a couple of uncoordinated eye movements. “I hit him with this new move I was testing out and it kinda knocked him over and when he got up- I basically had to pick him up myself- he seemed a little off and then he said he wanted to stop for the day and threw up and like- fell.”
“Ok, take a deep breath, Bakugo,” Aizawa says. “What’s he doing now?”
“Just kind of staring at the ceiling.”
“Is one of his pupils bigger than the other?”
“I don’t- yes, yes they’re different.” Bakugo uses his thumb and pointer finger to pull open Kirishima’s eyelids, and sure enough, his left pupil swallows nearly all of his eye’s color.
“He probably just has a concussion,” Aizawa soothes. He sounds very calm, and it’s kind of helping Bakugo settle. “Don’t worry, Bakugo, I’m almost there. You and I will take him up to Recovery Girl. It’s ok.”
“I didn’t mean to hurt him.” Bakugo’s voice breaks as tears well in his eyes. “I wasn’t trying to- he’s supposed to be, like, unbreakable, you know.”
“It’s not your fault,” Aizawa assures him. A door can be heard opening, then Aizawa hangs up. Before Bakugo can panic, the man himself comes through the training room door.
“I’m sorry,” says Bakugo. “Really, I didn’t mean to do this.”
“It’s ok,” Aizawa promises, sitting on Kirishima’s other side. He pulls a tiny flashlight from his pocket and shines it in Kirishima’s eyes. He flinches but only a little, and his eyes take several seconds to truly react, and when they finally do, his pupils hardly constrict like they’re meant to. Aizawa doesn’t make any indications that he’s worried, but Bakugo knows that it’s bad. “Alright, definitely a concussion.”
“A bad one,” Bakugo murmurs, wringing his hands.
“Nothing Recovery Girl can’t fix,” Aizawa dismisses. “Help me carry him.” Together they lift Kirishima off the floor, an arm around each of their shoulders. “Really, Bakugo, he’s going to be fine.”
Sure enough, Recovery Girl is able to heal him of his concussion, with only a touch of lingering pain. They’re back to training two days later.