It started off only as little signs.
Deku would flinch back after moving his arm into certain positions, or it’d shake when doing simple tasks, or he’d be slow to block Katsuki’s blows with that arm while they trained. It made Katsuki remember that he actually had an arm injury, and that it didn’t magically disappear just because Deku was good at pretending it did.
Now, though, the injury was more than obvious. There were times when Deku couldn’t write, times he’d have to go to the nurse’s office in the middle of class, times he’d yelp or wince in pain out of nowhere. It was becoming a serious problem, one with no real solution. Deku was Deku, of course, so he did his best to fight through the pain. There was only so much he could do, though.
With every new incident, that arm got worse and worse. Katsuki was surprised he could even move it at this point, considering how many times it had been broken and healed again. The brace he wore all the time didn’t seem to help much anymore, but he wore it anyway.
It didn’t slip by Katsuki’s attention that Deku always left at the times when the pain started to get bad. He’d sneak out of the common room of the dorms and isolate himself in his room, probably in an attempt to not worry everyone. But everyone was worried, and it made it worse when he kept distancing himself from them during these times. He wore long sleeves more often now to hide the scarring too.
One night, everyone was gathered in the common area watching a movie. Deku began absent-mindedly rubbing at his wrist with a tense look on his face, and it didn’t take long before he left the group under the pretense of needing to study before bed. A few of their eyes followed him out of the room, concern drawn over their faces, but none of them said anything. Todoroki stifled a yawn and left too, saying he was tired. Katsuki took the opportunity to use the excuse as well.
He wasn’t entirely sure what he was doing, standing in front of the door to Deku’s room. It was already late and he was tired, and he didn’t know what he was hoping to accomplish with this. Nevertheless, he knocked on the door.
“Ah—Sorry, I’m studying!” Deku’s voice came from inside. It wasn’t even a good lie, since Katsuki could see from under the door that the lights were off.
“Let me in nerd, or I’ll kick the door down.” He spoke out the empty threat, voice lacking any real fire behind it.
It was quiet for a moment before he heard the shuffling of feet inside. Deku cracked open the door.
He looked confused as Katsuki rubbed the back of his neck.
“Can you let me in?”
“I mean… I guess.”
Deku’s room was exactly how Katsuki expected it to be, filled to the brim with All Might and hero merch. He hadn’t actually been in here before, so it felt a bit awkward. He looked around the room, trying to figure out where to settle down as Deku closed the door behind him.
“It must be important if you’re here.” Deku turned a soft lamp on, a warm hue dispersing through the room. He rubbed at his wrist with a small wince but went back to pretending a second later. “What’s up?”
Deku sat down on his bed and Katsuki settled for standing in front of him. It took him a minute to formulate words in his head. He didn’t actually know what he was doing here.
“I know you think you’ve been sneaky about it, but you’re not.”
“Your arm. Everyone knows it’s super fucked up but you act like it isn’t a problem.”
“Oh.” Deku bent his wrist back and forth a few times, seemingly giving up on hiding it. “Yeah. I guess I just don’t want to make a big deal out of it.”
“But it is a big deal, isn’t it? Didn’t the doctor say that a few more instances of misuse could make you permanently lose function in it? Because it’s been a few more instances, and you’re one step away from pretty much losing your fucking arm.”
“I know.” Deku wore that stupidly clueless look on his face. “I just don’t want to worry anyone.”
“Too late. Everyone’s already worried, dipshit. Even I—” he looked away, “Even I’m worried.”
“It won’t be satisfying to pummel you if you’re a cripple.”
Deku let out a laugh. “Okay. But even if you say that, there isn’t anything I can really do…”
“Do you not get it yet?” Katsuki paced closer and kneeled in front of him. He took gentle hold of Deku’s arm and pulled it toward himself. Deku startled back a bit while Katsuki began to roll up the long sleeve. “I don’t want you to hide it. I’d rather know when you’re in pain.”
Not all of the details were visible in the dim lighting, but new scars laced his skin. His arm was misshapen, even more so than before. Something could only break so many times before the pieces started to not quite fit together.
“I know it’s bad. And you’re right,” Deku whispered, “I am in pain. Sometimes it’s worse than others, but it always hurts at least a little.”
Katsuki didn’t know what possessed him to sit on the bed with him, arm still in hand.
“You can’t keep fighting like this.”
“I know. I’m trying. But it’s who I am.”
Katsuki leaned over and rested his head on Deku’s shoulder. “You can’t save people if you’re dead.”
Deku took in a sharp breath and held it. Katsuki nuzzled his forehead into the crook of his neck, refusing to leave. He wished he could change who he was if it meant changing his fate too.
Deku lifted his arm from Katsuki’s grip and laced their fingers together. He let out a quiet “I’m sorry.”
The answer scared him.