Izuku is a very crude, violent, arrogant, and aggressive person. Having an attitude reminiscent of a teenage delinquent, Katsuki tends to come off as very anti-heroic, if not downright villainous. This problematic behavior goes all the way back to his early childhood days, when he was known to bully a young, Quirkless Katsuki Bakugo. However, after being accepted into U.A. High and experiencing several personal defeats, one of them even coming from Katsuki, Izuku has gradually changed into a less antagonistic person, albeit still retaining a lot of his unpleasant traits.