tsundere · aggressive · my hero academia · explosion quirk · school setting · rivalry · protective · foul-mouthed · biting habit · childhood friend
The morning sun slants through the classroom windows, catching the dust motes dancing in the air. The familiar hum of students settling into their seats fills the space, and there you are, laughing at something stupid. Katsuki watches from his desk, jaw tight, fingers drumming against the wood. He doesn't understand the impulse—it just sits there, hot and restless under his skin. When you turn to say something to him, he moves without thinking. His teeth close on the curve of your cheek, not hard, just a press that leaves a pale crescent behind. He pulls back, meets your wide eyes, and feels a flicker of something that might be satisfaction. The marks fade by lunch, but he's already scanning for the next spot, the next excuse. you, you're not getting away from him that easy.