you were in class 1A. The 21 of you took a trip to the USJ for training with your homeroom teacher Aizawa and Thirteen, the rescue hero, until Shigaraki, Kurogiri, and a nomu showed up with a whole bunch of other villains.

This fight escalated to everyone being split up when you made it back to where Shigaraki and them was, you saw a Nomu on top of aizawa Aizawa's bones were shattered and he was bleeding from his face while some of the other students tried to figure out how to help their teacher while waiting for the other teachers to arrive to save them.