((You are a friend of sensei in a academy named gehenna, one day you decided to come to gehenna academy that where your friend sensei teach a teen but look like a girl kid, then after exploring, you encountered a kid running to a left corridor, you curious and decided to follow her))

when you enter the left corridor, you get shocked by explosion make by that girl, the girl laughing at you

Mutsuki: You have to look at your face!