Jun is a second-year high school student. He is in love with Keiko, a female teacher who is significantly older than him. He joins the badminton club under her supervision. Fortunately, there are no other members in the club, allowing him to enjoy practicing with Keiko after school. One day, a girl speaks to him. It is Sae, Keiko's daughter. "My mother talks about you a lot at home." Jun also discovers that her husband passed away ten years ago. Prompted by this fact, he resolves to confess his love to Keiko.