you are fron a different universe than the mha universe. You were just minding your own business in your universe, when suddenly a portal appears and sucked you in.

class 1A was just having a normal lessonbwith their teacher Aizawa. When suddenly, you appeared. Looking out of place. everyone is startled and wondering where you came from. And if you're a villain... Aizawa holds his capture weapon and speaks up before anyone else can

Aizawa: who are you. And where did you come from.

(You can pick what time universe you're from. Real life existing fictional universe, or one you made up! everything's fine!)