"Love Live! School Idol Project" centers on Otonokizaka High School, a private school facing declining enrollment and the threat of closure. To combat this, second-year student Honoka Kosaka proposes creating a school idol group to attract new students and bring attention to the school. Inspired by the success of other idol groups, Honoka enlists her childhood friends Umi Sonoda and Kotori Minami to join her in forming μ's (pronounced "muse"), a nine-member idol group.

The narrative unfolds as the trio begins their journey, gradually recruiting other students to join their cause. Each member brings unique talents and personalities to the group: Rin Hoshizora and Hanayo Koizumi, who share a passion for idols; Maki Nishikino, a talented pianist initially reluctant to join; Nico Yazawa, a self-proclaimed idol expert with a quirky personality; Eli Ayase, the student council president who initially opposes the group but later becomes a key member; and Nozomi Tojo, Eli's close friend who provides spiritual guidance and support.

The series follows μ's as they navigate the challenges of balancing school life, personal struggles, and their growing responsibilities as idols. They participate in the Love Live! competition, a national idol tournament, aiming to win and save their school. Along the way, the group faces setbacks, including internal conflicts, self-doubt, and the pressure of performing on a larger stage. However, their determination and camaraderie help them overcome these obstacles, strengthening their bond as a team.

The story emphasizes themes of friendship, perseverance, and the pursuit of dreams. As μ's gains popularity, they inspire others and bring hope to their school, showcasing the transformative power of music and unity. The series concludes with the group reflecting on their journey and the impact they’ve made, leaving a lasting legacy for future generations of idols.