Motoharu (Tadayoshi Okura) and Mio (Alice Hirose) have been married for 5 years and they have two children. Motoharu works at a bank. He is stressed over his work and his boss. At home, he is constantly scolded by his wife Mio. They first met when Motoharu was a college student and he tutored Mio who was a high school student. They fell in love and married. Back then, Mio was bright and cute. Now, she is completely different and yells often at Motoharu. While drinking with his friends, Motoharu complains that his wife is a monster.
Motoharu happens to meet a woman who attended the same university. She was popular among the male students and she tells him that she liked him back then. Motoharu wonders what if he chose her. One day, he receives a 500 yen coin from a man. Due to the coin, Motoharu travels back to his university days.
