Tabuchi, the chairman of a famous company, is worried about his virgin son who is about to turn 30. Thinking that marriage might bring about changes in such a son, he uses his power to force a meeting between his son and Nao, the daughter of a subcontracting company manager, under the pretense of an arranged marriage. However, Tabuchi is actually plotting to make Nao his own. He quickly moves ahead with the marriage proposal without asking for Nao's consent, and pretends to be a strict father who forbids premarital sex. Then, on the day that he sends his son off on a five-day business trip, he puts Nao's training plan into action...