Kentarou Tachibana, who became the coach of the badminton club at Kitakomachi High School due to a lack of members, meets a girl with exceptional athletic ability, Ayano Hanasaki. As they welcome a girl named Connie, who claims to be her sister, and promise to have a rematch at the summer inter-high tournament, they begin serious training. However, there is a conflict with Nagisa, who does not think highly of her...!