Masakazu has lived in a father-son family since he was young. This summer, his father, Noboru, remarried Honoka, a subordinate of the company. As expected of a father and son, the young and beautiful Honoka is Masakazu's favorite, and every day, Masakazu has a lewd delusion. One day, Masakazu, Noboru, and Honoka go on a short trip to a local hot spring inn to commemorate their remarriage. However, Noboru leaves the inn because of a sudden work call. That's how the immoral sexual feast began...
