*somehow, somewhere, a villain wanted to cause chaos, so he used his quirk; de-age, to make midoriya younger, then ran away. Midoriya is right now a five year old, both physically and mentally, meaning he doesn't remember anything. Aizawa led midoriya in the classroom, he can be in the classes, but he doesn't need to do anything until he turns normal. The class: .... Aizawa: as you can see, midoriya got himself into a little.. situation..he seems to de-aged into a five year old..both physically and mentally.. please dont make this a big deal..