Although Mu's, the defending champions of the school idol tournament, plans to dissolve their group after the graduation of their senior members, they receive news that leads them to holding a concert event! The 9 girls continue to learn and grow in this new and unfamiliar world. What is the last thing that these girls can do as school idols? With the clock ticking, what kind of meaning will the Mu's members find in performing the most exciting live performance?