When his father remarried, Ryota suddenly had a new stepmother, Yu. Always smiling and with an attractive body, Ryota, who is of marriageable age, becomes infatuated with her. However, the other woman is his father's second wife. Ryota had given up on the idea of a love that would never come true, but suddenly an opportunity presents itself. His father is going to be away from home for three days on a company trip. Ryota cannot miss this once-in-a-lifetime opportunity. Now that they are finally alone, Ryota attacks Yu in an attempt to get her to notice him.