Haruka Nanase begins his first year at Iwatobi Middle School. After discovering that Haruka and his childhood friend, Makoto Tachibana, had once been part of the Iwatobi Swim Club, Asahi Shiina urges them to join the swim team despite Haruka's lack of interest, while Kisumi Shigino suggests they join the basketball team. Natsuya Kirishima, the captain of the swim team, visits their class and successfully convinces Haruka, Makoto, Asahi, and his younger brother Ikuya to join.