LOVE LIVE! SUNSHINE!! THE SCHOOL IDOL MOVIE: OVER THE RAINBOW

In the film's story, Uranohoshi Girls' High School's idol group Aqours has won the final Love Live! contest. While preparing to enroll at a new school, the first- and second-year students encounter unexpected trouble. Also, after heading for a graduation trip, the third-year students go missing. As they are separated, the Aqours members appreciate the weight of their togetherness for the first time. In order to move forward, they must decide how to react to their new situations. (Source: Official Website) — Description from AniList community (anilist.co).