"Action Heroine Cheer Fruits" is set in Hinano City, a small town facing economic decline due to the closure of its local shopping district. To revitalize the area, the city council decides to create a live-action hero show featuring local girls as heroines, inspired by the popularity of similar shows in larger cities. The series centers on a group of high school girls who take on the roles of these heroines, combining their efforts to save their town while navigating personal challenges and growing as individuals.

The protagonist, Mikan Kise, is a cheerful and energetic girl who initially lacks confidence but becomes inspired to join the project after witnessing a live-action hero show. She is joined by her childhood friend, Ann Akagi, a reserved and serious girl who harbors a secret passion for hero shows. Together, they form the core of the team, recruiting other classmates and friends to participate. These include Misaki Shirogane, a former idol seeking a new purpose; Yūka Mizushima, a skilled martial artist with a competitive streak; and Kokona Ōmori, a shy girl who discovers her inner strength through the project.

As the girls work together to create their hero show, they face various obstacles, including budget constraints, creative differences, and the pressure of performing in front of an audience. Each episode focuses on their efforts to produce a new installment of the show, blending humor, drama, and action as they tackle both personal and external challenges. The series also explores the impact of their performances on the town, gradually drawing in more visitors and revitalizing the local economy.

The narrative emphasizes themes of teamwork, perseverance, and self-discovery, as the characters learn to overcome their insecurities and work together toward a common goal. The live-action hero show serves as a metaphor for their growth, with each performance reflecting their evolving confidence and camaraderie. By the end of the series, the girls not only succeed in saving their town but also forge lasting friendships and a sense of purpose.