Moemi is not overly pleased when Yukio brings home a couple of turtles to keep her company. Their lives seem reasonably happy until she has her braces removed, and Yukio finds kissing her less satisfying. She soon starts tying up everything in her sight with knotted twine, starting with the turtles. A psychiatrist diagnoses "Obsessive Knot-Binding Syndrome" due to deficiencies in her relationship with Yukio. Moemi continues to expand her activities, tying herself in knots with cords stretching across the apartment. The doctor tells Yukio that her illness has reached a critical point, and that he should tie her up that evening. This he proceeds to do, with her encouraging him to bind her more and more. Where will this end?