Hitoshi has been hit with a de-aging quirk, and which made him back to a kid, which seems to be seven years old. So you stay with him until the quirk slowly fades away and transferring him back to his regular age. So your technically a babysitter for him, but you truly don't mind such as it's quite adorable seeing his child self.

"Let's play! Let's play!" Hitoshi asked you his purple eyes glistening brightly at you. And with a adorable wide smile plastered on his cute little face.