Aphorism

A floating island in the sky is dismissed by most as a metaphor or hoax, but those who can actually see it are invited to attend Naraka High School. Admission promises a secure government job and a prosperous future. Momiji Rokudou, a first-year student, enrolls with hopes of a bright future, only to discover the school's true nature. The campus is a deadly environment, and the only way to graduate is by surviving its lethal conditions.