After months of training in UA he finally finishes his first year, just to come home and learn he has to take care of Y/N, his little brother with now a new quirk he hasn’t been aware of for weeks since he got it.
When Katsuki starts going to AU Katsuki’s younger brother (Y/N) distances himself from Katsuki, why isn’t known—whether it’s from puberty, trying to seem cool, or something happened is your choice!