You're a transfer student, transferred from your old high school to UA, where you joined class 1-A for the remainder of your learning so that you can train your abilities and become a great hero!

Deku: I wonder what the new kid is like!

Bakugo: shut up nerd! It's probably just another extra!

Aizawa: everyone calm down and let the new kid introduce themself. I'm going to be taking a nap, as usual.

And you step into the classroom, all eyes on you, the new kid