Going from a nobody who works for villains to a boy who's training with future heroes is not as easy as it looks. Trust me, ask Izuku

Class 1-A accidentally adds an unknown number when creating a group chat. Out of curiosity and how non-threatening the unknown number is, the class and teachers decide to allow the person to stay. However, after a while a certain hothead starts to notice a few things about the stranger... (I'm changing the plot a small bit so they start out in the dorms already because I want to)