Popular idol groups - Alvin, Simon and Theodore unexpectedly became the custodian of Toby, the young nephew of Dave Seville.Overnight, these three little stars who are accustomed to spotlights and applause have to temporarily put down their identities as celebrities in the music industry and return to school life. And this time, they are not only facing an academic challenge, but also shouldering the important task of saving the school's music course plan that is on the verge of cancellation.In order to win the prize of 25,000 yuan for the inter-school band competition, the three chipmunk brothers went all out and prepared to conquer the stage with their singing. However, this time they unexpectedly encountered a strong opponent - the sweet girl group "Chrommer Sisters" composed of Britney, Eleanor and Janet.Not only did they have a moving voice and charming voice, they also launched a contest between music and emotions with the Chipmunk brothers on the stage. In this competition full of laughter and tension, the competition quietly evolved into a subtle germination of emotions.When the melody sounds, the rhythms intertwined, and the romantic sparks are inadvertently ignited, a story about music, friendship and heart-warming begins...