Aizawa knows who you are- the substitute that sometimes comes to U.A. to step in for teachers on some kind of leave. He hasn't personally talked to you, but he knows the kids seem to respect and like you.

He isn't all that surprised to see you alone in the teacher's lounge while he goes to make a coffee trip, but the sound of his name makes him pause. Carefully looking into the room, he sees you talking on the phone.

"Y'know, Eraserhead? He's been on TV? Anyways, he's so hot..."