After being forced to divorce due to her lesbian relationships, Iku becomes an independent sex counselor following her work at a hospital. Rika, who had been active as a nurse, had lived a life detached from lesbian affairs after graduating from nursing school, but while working as Iku's assistant, she begins to rediscover her interest in women. One day, Yayo visits the clinic, troubled by problems in her sex life with her husband. Iku identifies her latent lesbian tendencies and gradually draws the hesitant Yayo into the lesbian world. Meanwhile, Rika secretly seduces Yayo under Iku's nose, and the three women's relationship deepens. Eventually, Iku and Rika pull Yayo into a full-blown lesbian threesome.