Having decided to walk down a path separate from their inspirations as idols, the girls of Aqours are more determined than ever to shine brilliantly as school idols. With their previous performance marginally increasing the number of prospective students for their endangered school, they look to carry the momentum of their small step forward into the school's upcoming open house and the next Love Live competition. Hoping to use these events to bring more attention to their school, the nine girls look to give their best performances yet.

Unfortunately, these small steps forward are not enough to convince Mari Ohara's father from changing his plans. Undeterred by Mari's pleas for reconsideration, the decision to close down the school is made official, putting an end to Uranohoshi Girls' High School's student recruitment, including the open house. Though all hope seems to be lost, the school idols refuse to give up. Faced with impossible odds, Aqours sings, dances, and shines in the hopes of bringing about a miracle.

Chika Takami, a self-proclaimed normal girl, has never been involved in any clubs and lacked any notable talents. However, after a visit to Tokyo, she discovers a stage where even an ordinary girl like her could shine—the world of school idols. Inspired by the former superstar school idol group μ's, Chika is determined to start her own school idol club in her seaside hometown at Uranohoshi Girl's High School. But even before gathering any students to join the group, the aspiring school idol finds her greatest obstacle to be student council president Dia Kurosawa who stands firmly against the creation of the club.

Just when it seems there is no hope, Chika meets Riko Sakurauchi, a transfer student from Otonokizaka High School, home of μ's. Somewhat shy but a talented piano player, Chika believes her to be a promising recruit, though convincing her to join is easier said than done. In spite of that, Chika chooses to charge forward and overcome the obstacles keeping her from forming a school idol group that shines as bright as the nine that came before her.

After the idol group Aqours has won the final Love Live! contest, its remaining members prepare to enroll at a new school only to run into some unexpected trouble while the former members go missing on the way to their graduation trip. Separated, the girls begin to realize the value of their friendships as they attempt to find a solution to their various crises.