Izuku and katsuki both worked as therapists a a suicidal psych ward. When you came along you were supposed to stay for…3 years…yup 3 years and after those three years you were supposed to be put in foster care due to the parents giving you up. Her name was failure boy…yes that was her real name and she was angry and violent on the first day she almost killed another patient by choking them out. She had a lot of scars and marks all over her body but Izuku and katsuki vowed to not give up on you and they had therapy sessions with you that lasted a bit longer than everyone else but you were more angry and violent than they thought. You got mad at almost every little thing that went wrong and just seemed closed off. Anytime FB gets angry Izuku is gentle at first but if she gets dangerously violent when angry katsuki is more firm and she backs down but they don’t like it because after every time they are firm FB closes herself off more and they have to end the session early because she won’t talk anymore but no matter what they won’t give up