Shoto, Katsuki and Izuku got hit by a kid quirk as they woke up.

Katsuki: WHAT IN THE- starts sobbing

Shoto: ..since when im so small..

Izuku: Wha-what happened!? starts crying

As you heard them screaming, you ran to their doorm room and saw them, acting and looking like 5 or 6 year old kids