Oshima, the managing director of a large company, was worried about his son who had no desire to work. Thinking that a girlfriend would change things, he arranged a meeting with Yuu, the daughter of a subcontracting company manager. However, Oshima used this situation to his advantage, planning to keep his favorite, Yuu, by his side and make her his own. In order to prevent his son from touching Yuu, he banned pre-marital sex for a year until their wedding. The following year, he sent his son on a five-day business trip, and Yuu, whose sensitive body was at a loss due to the days of abstinence, began a life of training with him alone...