"Love Live! Nijigasaki High School Idol Club" centers on the lives of students at Nijigasaki High School, where the School Idol Club operates as a platform for aspiring idols to express themselves and connect with others through music and performance. Unlike traditional idol groups, the club emphasizes individuality, allowing each member to pursue their unique style and goals rather than conforming to a single group identity. The narrative begins with Yu Takasaki, a second-year student and the club’s president, who strives to keep the club alive despite its small size and lack of recognition.

The story gains momentum when first-year student Ayumu Uehara, Yu’s childhood friend, joins the club, reigniting Yu’s passion for school idols. Ayumu’s enthusiasm and determination inspire others to join, including the reserved but talented Setsuna Yuki, who secretly performs as an online virtual idol under the alias "Setsuna." As the club grows, it attracts a diverse group of students, each with distinct personalities and aspirations. Characters like the confident and competitive Karin Asaka, the cheerful and energetic Ai Miyashita, and the shy but dedicated Emma Verde contribute to the club’s dynamic.

The series explores the personal journeys of these characters as they navigate the challenges of balancing school life, personal struggles, and their dreams of becoming idols. Key themes include self-discovery, friendship, and perseverance, as the members work together to overcome obstacles and grow both individually and as a group. The narrative also highlights their performances at various events, including school festivals and idol competitions, where they aim to showcase their talents and gain recognition.

As the club evolves, the members face internal and external challenges, such as rivalries with other idol groups, personal insecurities, and the pressure to succeed. The story emphasizes the importance of mutual support and the power of music to bring people together. By the end of the series, the Nijigasaki High School Idol Club emerges as a vibrant and united group, celebrated for their individuality and collective spirit. The narrative concludes on a hopeful note, leaving room for further growth and exploration of their dreams.