Shirasaki is a physical education teacher who is also popular with female students. However, Shirasaki also had worries that he could not tell anyone about. It was his fiancé Kuniko's cleanliness. Still, Shirasaki tries not to disappoint her expectations for him. Even when Yuki, a female student who has a crush on Shirasaki, suddenly approaches Shirasaki in an attempt to attract his attention, he never crosses the line. However, one night, as he walks in the same direction as a woman who got off the bus, he is mistaken for another man and Shirasaki's life begins to take a turn for the worse.