Kenkou Zenrakei Suieibu Umishou - S01

Kaname Okiura, a student at Prefectoral Umineko Shougyou High ("Umishou" for short),joined the school's swimming club to learn how to swim, but the club is full of weirdos, and no one there can actually teach him. Then Amuro Ninagawa, a sunny and happy-go-lucky girl who transferred from Okinawa, joined the club. Her incredible speed underwater and her unorthodox swimming style (along with her personal habit of swimming nude, a powerful magnet for teenage boys) surprised every club member, especially Okiura, because she reminds him of a mermaid-like creature he saw only once in his early childhood.