A horror variety that looks back on the mouth split woman who pioneered the urban legendary boom. At the end of the 1970s, a tearing mouth woman suddenly fears people. Tell the truth of the rumor by giving specific examples such as who she is, its identity and appearance, how to repel.

Taiga wakes up in an unknown place, next to Niina with whom he had lost contact. Confined in a school with former elementary school classmates and their teacher, they find themselves forced to participate to a sadistic game: "The Werewolf's game".