Listen to Your Heart

Maybe it's the blood still rushing through his veins. Or it's just the happiness Katsuki has now that he's beaten those assholes to a pulp. But, in any case, he's feeling a lot more positive about life in general or maybe he's just light-headed from taking a punch or two to the face. He examines Izuku. A line of someone else's blood dribbles down his chin, and a bruise swells on his forehead. Izuku catches him staring.

"Is there–how bad?" He asks nervously, putting his hands up to his cheeks.

"You look as dumb as usual." Katsuki answers, quickly looking away from Izuku's startlingly green eyes. "Does it hurt?"

"Huh?" Izuku stops walking. 

Katsuki stops a few feet farther on. "Does it hurt?" He repeats. "Your face," he clarifies.

Izuku gapes at him.

"Is it that weird for me to be worried?" Katsuki snaps, feeling the heat rising in his face.

"N-not really."

"Good, 'cause I do worry. You're a dumb, stubborn piece of shit who never runs away when he should. What kind of friend would I be if I didn't worry? And–" He cuts off abruptly. "Are you crying?"

Indeed, he is. Katsuki awkwardly falls silent, unsure of what he said to elicit that kind of reaction.

Izuku sniffles loudly his eyes streaming with tears. 

"Did I say something wrong?" Katsuki asks.

Izuku takes a minute to calm himself, and when he does answer, his words are muffled by his hands. Katsuki hears them clearly all the same:

"I'm just really glad we're friends."

After that, they continue to the apartment complex where they live. Without thinking about it, Katsuki's feet lead him to the front of Izuku's apartment. Midoriya Inko opens the door, and cries almost as much as Izuku when she sees their bruised faces. She fusses over them for nearly an entire hour before she's convinced that they are, in fact, not dying and will be alright. Katsuki gratefully closes the door to Izuku's room.

When he wakes in the morning, Katsuki stares at the ceiling of a room that's not his own but is almost as familiar. It's warm with the sun filtering through the window and his fingers tangled with Izuku's. This comfort and peace is something Katsuki realizes he wants to hold onto and something he thinks he doesn't quite deserve.

As autumn turns to winter, Katsuki continues to train with his mother. She works him hard but always makes sure to remind him not to strain his growing body and to let himself rest. He vaguely remembers how he trained at UA and how he can strengthen his quirk, so he tries that, too. As they graduate from elementary school and enter middle school, he gains several centimeters on Izuku in height and a lot more weight in muscle.

Izuku is quiet beside him and still shy, but more easily outspoken about his thoughts. He shares the notes he keeps on heroes, and Katsuki tries not to think of notebook number 13. 

In middle school, a few kids try to tease Izuku for being quirkless, but Katsuki silences them quickly. Their years seem to be passing by too quickly. Katsuki knows their high school years will be fraught with danger, but the more he tries to cling onto peaceful moments, the faster they seem to slip away. 

As he gets older, the nightmares start to worsen. He still dreams of the same day. The same screams. The same agony. Most nights he wakes up alone in his dark room, cursing himself for being so dependent on Izuku to calm him. 

As he gets older, there starts to be an uncomfortable flutter in his chest when Izuku reaches for his hand or smiles at him softly. He's fourteen, and their male classmates start pulling the girls' pigtails and whispering about the wonders of swimsuit magazines and other things. Izuku tends to go red when these topics appear in conversation, and there's something about his expression at those times that Katsuki doesn't like.

It's only when he overhears a (very loud and giggly) conversation between a group of girls in their class that Katsuki puts together the butterflies in his stomach and the reason he gets uncomfortable when the other boys talk about girls. He overhears them talking about a flutter in their chests when so-and-so looks their way or don't-his-eyes-look-just-beautiful. 

Katsuki walks away very quickly, but not fast enough to avoid the realization that he has a horrible, irrevocable crush on his best friend.