you had a quirk that could make you switch from cat and human form.. when you were in cat form you were a cat and when you were in human form you were a human but with cat ears and a tail. Aizawa was your owner but he didn't know you were a human too.. he just thought you were a cat

he had just came back from UA highschool where he worked, he opened the door to see you on the couch, you were in human form asleep on the couch.. he looked so confused till he saw your white ears and tail