Work Text:
It falls out of an old volume of manga while he's straightening, keeping the place tidy and taking the extra time to arrange sensei's books by title and author. He doesn't recognize the figure at first, thinking it might be a photo the previous owner had shoved in the book; sensei bought his books secondhand and had found receipts, notes, and letters before.
He holds the thin paper between his fingers, turning it over. It has to be sensei--the blue track suit covered in various stains and sweat still hangs in sensei's closet. He poses with the defeated corpse of a monster, splattered across the pavement. Dark hair frames his face; it seems as though it had been intended to be a specific haircut, and had grown out over time. He smiles, half confident and half embarrassed as he glances at the camera.
Genos doesn't realize five minutes pass by the time he finally tears his gaze away from the photo. He has never seen sensei so young, and as far as he knows, no photos of him even exist besides the manditory profile picture on the Hero Association's website.
He knows, he has checked before.
Sensei seemed to be...perhaps 20 years old? Maybe 21. Just beginning his hero work, and already vanquishing evil with ease.
Genos presses the picture to his chest, his core gently whirring. He would be 14 or 15, then. Right around the disaster.
Had sensei been anywhere near his city when it happened? If he were, he would have come. He would have seen the mad cyborg, and destroyed it with a hit that could shatter buildings. He would have been there to pull a shaking teenager from the rubble.
Genos closes his eyes for brief moment. A thin, dark haired kid with tears in his eyes and a round face that sharply contrasted his current appearance. Sensei calms him down, takes him by the shoulders and makes him stand steadily. His body is still intact, and he can feel sensei smoothing back his hair. Telling him it will be okay. It will be okay.
He falls to his knees and begs to become his disciple. His assistant. Anything. He doesn't want to be left alone here.
It takes the older man a moment, but he accepts because he is younger and kinder and softer and the loneliness burns more. Strength has not hardened his heart yet.
He travels with him, defeating evil and saving the innocent. Learning is a slow process but rewarding.
He...transitions. Like anyone else would. He binds his chest and cuts the dark hair, bleaching it blond. His voice grows deeper with age and hormones. Sensei doesn't mind.
They have fun. Genos teases him when his hair finally falls out, and it's okay because when the testosterone thins his hair a little too sensei makes ample fun of it. They have eating contests, and it's a real competition. They clean together, at normal, human paces. They sing off key.
He sighs, deep and whirring. A vent on his shoulder opens and releases a steady stream of vapor.
Genos grabs his notebook and carefully tucks the photo into its pages, making a note to laminate it later. It has to be saved.