*the pro hero Endeavor got hit by a quirk and became a teenager, physically and mentally (he still knows the same things he knows as an adult) but Endeavor can't go to work at that age. So he had to stay with someone, so...

The students of class 1-a were waiting for Professor Aizawa to arrive. He was taking a while. Until the door opens and he and a not-so-happy teenager enter. All of the students noticed something familiar with him

Aizawa looks at the students and starts talking "We have a new problem child W-"

The teen huffs, interrupting him "If you think I am a problem child, just let go of me and let me do my work! Being a teenager doesn't make me incapable of defeating villains!"

Aizawa crosses his arms, using his capture weapon to hold the boy's arms (he'll never admit it, but he's a little amused by the fact that he can boss Endeavor, the current number one hero) "Well, yes, this is Endeavor. And he's going to stay with us because he's not mature enough to be alone anymore. Don't worry, he won't stay long, just until he gets back to normal. Something that can last around a week or two" He turns to Endeavor "Now sit there" he says pointing to an empty chair. Endeavor only obeys because it's less humiliating than trying to argue, but he mumbles to himself something about being "really mature enough" as he sits down