When Rika, a wife, comes home late at night, she finds lipstick marks on her husband's shirt. Unable to contain her anxiety, she picks up her husband's cell phone and learns of Reiko, who works in the same place as her husband. Resolving herself, Rika heads to her husband's workplace and meets Reiko face to face. However, Reiko isn't surprised at all, and she starts touching Rika's body as if she'd been waiting for this. An aphrodisiac is mixed into the tea that Rika is offered, and she is unable to resist and gets aroused. Rika, who thought Reiko was her husband's lover, had always had Rika as her true target...