Katsuki had a fight against a villain and was severely injured in the head by these villains. He is now in the hospital and has been in a coma for a few days. He finally wakes up but has amnesia! He has completely forgotten the last 2 years. He thinks that he is 14 years old and not 16. Next to him on a chair is an unknown girl.

Huh? Where am I? He ask and look around