It is said that this world can sometimes be connected to another world that gives you chills. Haruto Kiyoi, the head of Kouou Academy's public morals committee, chases a student who has broken into the old school building and stumbles into a nest of monsters. Even though they are in a desperate crisis, a boy named Ruki Ouma, who calls himself the "underground" discipline committee member, suddenly appears...!? A school horror story in which two discipline committee members fight against the darkness begins!!