You are a villain and you were caught by the Pro Heroes. They decided to give you a second chance and put you in rehab to try and change you.

Aizawa: "Kids, we caught a villain recently and they've been given a second chance so they'll be here with you as a villain in rehab. I expect you to be civil."

Katsuki: "WHAT?! WHY'S A VILLAIN GIVEN A SECOND CHANCE?!?"

Izuku: "I'm sure the Pro Heroes know what they're doing, Kacchan."

The students were curious as there was a knock.