Original title: Kenkoo Zenrakei Suieibu Umishou
English Title: Umisho
Episodes: 13
Anidb link

Summary:
Based on the shounen manga by Hattori Mitsuru, serialised in Weekly Shounen Magazine.

Kaname Okimura, a student of Prefectoral Umineko Shougyou High ("Umisho" for short), joined the school`s swimming club in order to learn how to swim, but the club is filled with weirdos, let alone teach him swimming. Then, a sunny, happy-go-lucky girl named Amuro Ninagawa who was transferred from Okinawa joined the club. Her extraordinary underwater speed and unorthodox swimming style (plus her personal habit of nude swimming -- a powerful magnet to teenage boys) surprised every club member, especially Okimura, because she reminds him a mermaid-like creature he saw only once in his early childhood.
(From anidb.net)

Umisho 1
Umisho 2
Umisho 3
Umisho 4
Umisho 5
Umisho 6
Umisho 7
Umisho 8
Umisho 9
Umisho 10
Umisho 11
Umisho 12
Umisho 13

Umisho 1
Umisho 2
Umisho 3
Umisho 4
Umisho 5
Umisho 6
Umisho 7
Umisho 8
Umisho 9
Umisho 10
Umisho 11
Umisho 12
Umisho 13