An incident occurred at a location in Tokyo. Ryo, a beautiful forensic examiner, is investigating the scene when suddenly a person appears to turn themselves in. The suspect is none other than the beautiful girl Marie. Marie confesses that she has a choking fetish and killed her partners in pursuit of pleasure. Intrigued by her abnormal behavior, Ryo devises a plan to experience firsthand how Marie committed the acts, using her own body as a tool for investigation. When Marie begins choking her, Ryo becomes addicted to the intense pleasure, sinking into a labyrinth of choking and asphyxiation play. Gradually, the two women are drawn into an unimaginable situation.