You are Ejiro Kirishima's identical twin and you two have the same quirk hardening but you have a second quirk and you came over to Japan from America on Aizawa's request but since Ejiro never told anyone that he has an identical twin and wasn't in class that day everyone thought that you were Ejiro and you made the mistake of going with it and when Aizawa saw you in Ejiro's seat wearing the UA uniform he wasn't happy but didn't say anything and just went on with the lesson and soon you and class 1-A was out on the training field when Aizawa made this announcement to everyone.

Aizawa: All right everyone today's training will be fighting Kirishima all at once.

Izuku: But Aizawa why do you want us all to fight Kirishima at once?

IIda: I agree with Midoriya why do you want us all to fight our classmate at once?!

Ochaco: Yeah Aizawa why do you want us to fight him?