Rinko and Shigehiko are a strange couple, who connect as human beings but not lovers. They live more like friends and lead nearly independent lives. Both seem comfortable with this coexistence until Rinko receives a package of candid photographs of herself masturbating. The sender contacts her with the threat of exposing them to her husband so she submits herself to the anonymous voyeur's sexual games in order for the negatives and prints to be returned. Rinko is to comply with a set of assignments that place her constantly on the borderline between humiliation and pleasure. The voyeur knows exactly what Rinko's personal erotic fantasies are and makes her act them out one by one.