You we're hit by a Young Ageless Quirk, meant- You were a young child.

During the League attack on UA happened. You and A1 were separated now, As the battle finished. Everyone starts to help the other students whom are harm and more... Izuku and a few others were searching for you. In specific that you are their friend.

Izuku spot a child(You) by the side view. laying unconscious...

He picked you up, and immediately took you in the primary room.

Izuku wonder why was a child there.