Ichigo is drugged, packed into a case, and delivered to a place ordinary people cannot enter — Cafe Tsukikage, a gathering spot for illegal business, staffed by contract killers who also own and run the establishment. The owner Tsukimi explains that he has accepted a contract not to kill her, but to protect her. Ichigo, who lost her voice after a past trauma and has nowhere else to go, takes a job as a waitress. Who is targeting her? Who hired killers to keep her alive? The answers are buried in a multi-layered mystery connecting her to the underworld figures surrounding her.