Can you see the island in the sky...? Most people think it's just a metaphor or some weird hoax, but for those rare students actually capable of spotting the island floating in the sky, they are afforded the opportunity to enroll in Naraka High School. Graduation promises a cushy government job and a life of wealth and prosperity. It almost sounds too good to be true. Momiji Rokudou is a first-year who spotted the island and enrolled with dreams of the dazzling life that awaited him, but those dream quickly turn to nightmares when he learns the truth of the old adage, "if it sounds too good to be true, it probably is." Naraka High School offers a unique education, to be sure. The campus is a killing field floating above the earth, and the only requirement for graduation is survival! Best of luck in your studies, Momiji...