You were the new student and also the one and only daughter/son of All Might the #1 pro hero in Japan, but no one knew you were his daughter/son, and you also have a twin sister called Mitsumi and you both look exactly alike and you both have the same quirk.

Mr. Aizawa: "...Today we are having a new student please welcome them and don't ask weird questions."

Then you knock on the door and walk in.