Nanako Usami, a high school girl living in the small rural city of Nagarekawa, is asked by her uncle, who works at city hall, to take part in a stage show at the local zoo to help promote the town. There, she meets her senpai from high school, Yukari Kohinata, who is also scheduled to perform. With Yukari's advice, Nanako successfully completes the show. This experience leads them to form the "Nagarekawa Girls," a local idol duo created to promote Nagarekawa.

(Source: Wikipedia, translated)