Based on 16-year-old writer Sarie Hinakura’s award winning story Jellyfish is centered around two adolescent girls disconnected from their immediate environment of school and mates. They first get together while staring into a jellyfish tank at a local aquarium. The relationship that ensues eventually faces tension from the divergent personalities of the two protagonists, one of whom explores a heterosexual relationship with a fellow student. Jealousy and the wrath of a lover spurned are inevitable spillovers.

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".