"This half," Izuku says, the sound of tape stretching out filling the background as he pulls it out and lays it on the floor, "is mine. Everything on this side of the line belongs to me. If you explode my things, Kacchan, I will throw yours out the window." He looks up seriously from where he kneels on the floor. Pointing to the other side, he says, "That half is-"

"My fucking half, I fucking know that, idiot." Katsuki snarled, one hand a tight fist and the other smoking. "Any of your shit that crosses the line is fair fucking game."

"Right," Izuku nodded. They had agreed to those terms. There were Rules, bitterly fought for, pinned to the back of the door. He pointed to the tape box at the doorway. "That's no man's land. You can walk there or I can walk there but we can't walk through there together."

"Don't be bringing any of your shitty little friends in, either. I don't want to fucking deal with even one of those little morons while I'm in here."

"That's not fair, Kacchan! You can bring Kirishima in here! I don't mind if you have friends over."

"We're not fucking friends. Shut the fuck up."

Izuku's smile, forced as it was so he could at least appear pleasant when dealing with Katsuki, faded. He stared at Katsuki in silence for a long minute before whispering, "Kirishima thinks you're friends. That's why he came with us to save you. He cares about you." After a moment, where Katsuki stared at him with wide eyes, Izuku asked in a slightly strained voice. "Are you going to throw away his friendship too, Kacchan? Doesn't it make you lonely, to have no friends at all?"

Katsuki took a step back, eyes growing even wider at the questions. Almost immediately, he took two steps forwards, literally toeing the line to snarl down at Izuku. "Shut the fuck up. You don't know what you're even fucking talking about you little shit."

Izuku turned his face away, which Katsuki took as submission. He shouldn't have. Katsuki smirked, leaning back. He opened his mouth to rub a little more dirt in the wound when Izuku stood abruptly. Green eyes bored holes into him as Izuku said, his voice sharper than Katsuki had ever heard it. "You're going to end up an nonredeemable fucking asshole if you continue to live like you're fucking better than everyone else, Kacchan. We're going to be heroes. What do you think that even means?!"

Katsuki clenched his teeth shut, his lips pulled back in a silent sneer. His hands shook with how tightly they were fisted at his sides. "Being a hero means never failing, never falling short, never stopping the fight- All Might didn't stop. I won't ever stop. Not even after I become the top hero! Nothing will get in my way and keep me from winning, Deku. Not even you."

"I don't want to stop you. I've never wanted to stop you!"

Katsuki rolled his eyes. Izuku shoved his chest, sending him staggering back, but he didn't cross the tape line. Katsuki recovered quickly, coming back to the edge, snarling. "You little shit, I'm gonna-"

"All I've ever wanted was to stand at your side!" Izuku shouts, eyes screwed shut, tears on his cheeks. "That's all I've ever wanted, Kacchan! But I can't have that! So if it's not me that is with you when you become the greatest, at least let me know you won't be alone! Kirishima is your fucking friend! Just accept it. Please!"

Silence descends around them. Katsuki steps back, feeling a tightness in his chest, a pressure behind his eyes- He abruptly turned away, blinking hard. Izuku's panting breath is the only sound before there's a knock at the door and a cautious "Um… Deku? Are you okay?"

He goes to the door to talk to his concerned friend while Katsuki turns to face his bed, shoulders shaking. If this is how it's going to be every day with him, he thinks to himself, staring resolutely at his pillow, this is going to be a long, long fucking semester.