"Love Live! Sunshine!!" is a Japanese anime series that centers on a group of high school girls who form an idol group to save their school from closure. The story is set in the coastal town of Uchiura, where Chika Takami, a second-year student at Uranohoshi Girls' High School, becomes inspired by the success of the legendary idol group μ's. Determined to follow in their footsteps, Chika decides to create her own idol group, Aqours, to bring attention to her school and prevent its shutdown.

Chika recruits her childhood friend, You Watanabe, and a shy transfer student, Riko Sakurauchi, who initially hesitates but eventually joins after discovering her passion for music. The trio begins practicing and performing, gradually attracting more members. Kanan Matsuura, a third-year student with prior idol experience, and her childhood friend, Dia Kurosawa, the student council president, initially oppose the idea but eventually join after recognizing the group's potential. Dia's younger sister, Ruby Kurosawa, also joins, along with Hanamaru Kunikida, a reserved girl with a love for books, and Yoshiko Tsushima, who adopts the persona of a self-proclaimed fallen angel. The group is completed by Mari Ohara, the cheerful and eccentric daughter of the school's chairman, who returns from studying abroad.

As Aqours grows, the members face numerous challenges, including balancing schoolwork with idol activities, overcoming personal insecurities, and dealing with rivalries. The group participates in the Love Live! competition, a national idol tournament, aiming to achieve the same level of fame as μ's. Throughout the series, the characters' relationships deepen, and they learn to support one another, both on and off the stage. The narrative emphasizes themes of friendship, perseverance, and the pursuit of dreams, as the girls work tirelessly to save their school and make their mark in the world of idols.