Aces are not permitted in beach volleyball. To win, each player must select one irreplaceable partner on whom they can trust on the sand court. That is what Haruka Oozora discovers on her first day in Okinawa after moving in with her grandma and cousin Kanata Higa. Haruka comes upon some ladies playing beach volleyball while exploring a local beach and is instantly encouraged to join them. When one of the females, Narumi Tooi, spots Kanata approaching the court, the friendly practice game escalates into a competition. Despite the fact that the two suffer a crushing setback, Haruka now understands the reason for her cousin's silent and aloof demeanor. Kanata and Narumi used to be great beach volleyball players.