Aki, the second wife, was living a happy life with her husband and his son Hiroshi. But last year, when her husband went on a six-month business trip, an incident occurred. Alone with her stepson... unable to bear the loneliness, Aki committed a one-night mistake with her son. What was supposed to be a one-time error drove her son's sanity away, and they began to indulge in their lust without regard for time or place, ultimately continuing to passionately seek each other even after her husband returned from his business trip.
