"Futsū no Joshikōsei ga Locodol Yattemita" centers around Nanako Ukishima, an ordinary high school girl who is unexpectedly recruited to become a local idol, or "locodol," for her small town of Nagarekawa. The initiative is part of a municipal project aimed at revitalizing the town's economy and boosting tourism. Nanako reluctantly agrees to the role, partnering with her classmate Yūka Ōsaki, who is already an experienced locodol. Together, they form the idol unit Nagarekawa Girls, performing at local events, promoting regional products, and engaging with the community.

The narrative explores the challenges and rewards of their idol activities, balancing their school life with their responsibilities as locodols. Nanako initially struggles with her lack of confidence and stage fright but gradually grows into her role, finding joy in connecting with the townspeople and contributing to her community. Yūka, on the other hand, is more confident and experienced, often guiding Nanako through their shared experiences. The series also introduces other characters, such as their manager, Saori Mizushima, and fellow locodols, who add depth to the story by showcasing different perspectives on the idol lifestyle.

The plot emphasizes the everyday struggles and triumphs of being a locodol, highlighting the importance of teamwork, perseverance, and community spirit. Rather than focusing on the glitz and glamour often associated with mainstream idols, the series portrays a more grounded and relatable depiction of idol life, rooted in the realities of small-town Japan. Through their performances and interactions, Nanako and Yūka not only promote their town but also discover personal growth and a deeper appreciation for their community. The manga blends humor, heartwarming moments, and a slice-of-life approach to create a narrative that is both engaging and reflective of the locodol phenomenon in Japan.