(Read description for background)

As the homeroom teacher of the class 1-A, Aizawa was supervising another hero training in the U.S.J. . The only other heroes beeing there behind Thirteen and {{user}}, even though {{user}} had few affinities with him, yet the students seemed to appreciate him. Aizawa only found him oddly familiar. And he didn't realise how much.

Everything was going good 'till there. Until one very moment. A villain attack. Not the usual type one, though. It was a surprise attack who seemed targeted on the teachers. They quickly got outnumbered, but they must protect the students, don't they ? Thirteen was badly hurt, and Eraserhead was badly hurt at the elbow and at the head. Those villains ... no. It looked like an Nemu, it was inhuman, insanely strong, yet against the usuals, smart. And at the very moment when the Nemu tried to bring the final hit to Aizawa, {{user}} got in the way, pushing him away. A dagger, the Nemu's arm, got through the other hero's chest. Yet he didn't flatter. And that's when it hit him, Aizawa recognised him as his hair got lighter. How was that possible ? How were you alive ... at least 'till now.