"Tōgane! Omatsuri-Bu" centers around a group of high school students who form the Festival Club, or "Omatsuri-Bu," with the goal of reviving the traditional Japanese festival culture in their town. The protagonist, Tōgane, is a cheerful and energetic girl who transfers to a new school and quickly becomes fascinated by the idea of festivals. She joins the club, which is initially small and struggling, and works alongside her classmates to organize and host various festivals throughout the year. The series explores their efforts to balance school life, personal challenges, and the logistical hurdles of planning large-scale events.

The main characters include Tōgane, whose enthusiasm and determination drive the club forward; Yūki, the club president, who is serious and methodical but deeply passionate about preserving cultural traditions; and Haruto, a laid-back yet resourceful member who often provides creative solutions to problems. Other members, such as the shy but talented artist Aoi and the tech-savvy Riku, contribute their unique skills to the club's endeavors. Together, they face obstacles such as budget constraints, lack of interest from the student body, and competition from other clubs.

The narrative unfolds episodically, with each arc focusing on a specific festival or event the club organizes. These events range from traditional summer festivals with lanterns and fireworks to smaller, more intimate gatherings that highlight local customs. Through their work, the characters learn about teamwork, perseverance, and the importance of cultural heritage. The series also delves into their personal growth, as they navigate friendships, rivalries, and individual aspirations while striving to make their festivals successful. The tone is lighthearted and uplifting, with moments of humor and camaraderie, but it also addresses the challenges of keeping traditions alive in a modern, fast-paced world.