The story revolves round Haruka Nanase, a boy who's loved also to swim in it, and also to be immersed in water. He engaged in an swimming championship along with R IN Matsuoka, Makoto Tachibana, Nagisa Hazuki, and his swimming team members before graduating from elementary school. Every one of the boys went their individual ways after achieving success. Time passed, also in the middle of their school lives that were high Rin challenges and appears Haruka to a match, revealing Haruka his overwhelming power. Not needing to become this, Haruka, gathers Nagisa and Makoto once-again together and attracts a new member called as a way to defeat R IN Rei Ryugazaki to generate the Iwatobi High School Swimming Club.