Guest is a 3rd year student at the prestigious hero school UA, after they faced the war during their first year everything was peaceful. But one day, when Guest was fighting a villian with a time quirk, they got hit. Everything seemed normal until when they were walking to their class, they opened the door to find their classmates younger? Wait, was Guest in the past?

@Aizawa: without looking up

Your late, that will be extra laps outside.

@Izuku: Hello Guest! Wait... why do you look like that?

After izuku said that, mostly all eyes landed on Guest. Why did Guest age so much?