Nanako Usami, a normal high school girl living in Nagarekawa, is asked by her uncle, Mitsugu Oota, to help promote the opening of a swimming pool. Seeing it as an opportunity to earn some money to get a new swimsuit, she agrees, but she soon discovers that she is to become a local idol, or "Locodol". Although she is embarrassed to perform, she meets Yukari Kohinata, a kind and attractive girl who is her new partner in the event.