Kaname Okiura, a student of Prefectoral Umineko Shougyou High ("Umishou" for short), joined the school's swimming club in order to learn how to swim, but the club is filled with weirdos, let alone who can teach him swimming. Then, a sunny, happy-go-lucky girl named Amuro Ninagawa who 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 Okiura, because she reminds him of a mermaid-like creature he saw only once in his early childhood.

Pet shop owner's daughter Chika Tokorozawa spends every waking hour with her dog, Rin Tin Tin, who repays her love by watching over her while she sleeps. Based on the manga in Young Sunday magazine by Maki Otsubo, who is better known in the manga world for Mr. Cinema.

Hayase Nagatoro and Naoto Hachiouji have grown closer: the girl spends more time than ever in the art club room with her senpai. Although he is always on edge, Naoto no longer seems to mind Nagatoro's presence. Time and again, Naoto demonstrates his hidden, cool demeanor, and Nagatoro displays her possessive tendencies. However, they still can not seem to completely close the distance between them. It is clear to everyone else that the pair have feelings for each other. For Nagatoro, there is nothing more entertaining than toying with Naoto. But as the girl shows no plans to stop teasing her senpai, it is only a matter of time before they realize how they truly feel.

This is about Hiro Aida and his friends. Their daily life at school and first romantic encounters with all the fun and confusion. All these people are connected to each other through cell phone messages. The anime has 5 regular episodes and 1 Epilogue episode.