Set in a solitary island school where only students who have caused problems are gathered, and communication from the world is cut off. Homura Itsuki comes to the school as a transfer student. At the school, there is a study group for the 19th-century French cruel drama "Grand Guignol", and Itsuki ends up joining that study group. In addition to the members of the study group, the teachers who manage them, the head chef, the mysterious new teacher, and other people who gather at the school are somewhat suspicious. And finally, a serial murder case like "Grand Guignol" occurs. On an isolated island with no way to escape, Itsuki and his friends are caught up in the vortex of fear of death and love and hate between men.