Working as a campaign staffer for a mayoral candidate, Kintaro is assigned to tutor his boss' attractive teenage daughter, Naoko Katsuda, who wants more from him than help with her math homework.

Kintaro has challenged the local swimming coach (and former Olympic athlete) to a race, but he first needs to learn how to swim. While training, however, his situation with the coach, Ayuko Hayami is compromised.