"Love Live! School Idol Project" centers on Otonokizaka High School, a school facing declining enrollment and the threat of closure. To save their school, second-year student Honoka Kosaka decides to form a school idol group, inspired by the success of other idol groups. She recruits her childhood friends Umi Sonoda and Kotori Minami, who initially hesitate but eventually agree to join. Together, they form μ's (pronounced "Muse"), a group dedicated to becoming popular enough to attract new students to Otonokizaka.

As the group begins, they face numerous challenges, including a lack of experience, limited resources, and skepticism from their peers. Honoka’s determination drives the group forward, and they gradually gain members: Rin Hoshizora, a cheerful and athletic girl; Maki Nishikino, a talented but reluctant pianist; Hanayo Koizumi, a shy idol enthusiast; and Nico Yazawa, a self-proclaimed idol veteran who initially opposes the group but later joins. The group is further rounded out by Eli Ayase, the strict student council president, and Nozomi Tojo, her close friend and advisor, both of whom initially oppose the idea of school idols but eventually become key members of μ's.

The narrative follows μ's as they navigate the competitive world of school idols, participating in events like the Love Live! competition, a national idol tournament. Each member contributes their unique talents and personalities, helping the group grow in skill and popularity. The series explores their struggles, such as balancing schoolwork and idol activities, overcoming self-doubt, and dealing with interpersonal conflicts. Themes of friendship, perseverance, and teamwork are central as the characters work together to achieve their shared goal of saving their school.

As μ's gains recognition, they face rival idol groups, including A-Rise, a highly successful and polished team. These rivalries push μ's to improve and refine their performances. The series culminates in their participation in the Love Live! competition, where they aim to prove themselves as top-tier idols. Throughout the story, the characters’ personal growth is highlighted, with each member overcoming their individual challenges and contributing to the group’s success.

The series is structured into two seasons, with the first focusing on the formation of μ's and their initial struggles, while the second delves deeper into their rise to prominence and the challenges of maintaining their success. A subsequent movie, "Love Live! The School Idol Movie," serves as an epilogue, exploring the group’s final performances and their legacy as they prepare to graduate and move on to new chapters in their lives. The story emphasizes the bonds between the characters and the impact of their shared journey, leaving a lasting impression on both the characters and the audience.