The story begins with the peaceful daily life of schoolgirls—which suddenly breaks down when former schoolmates become zombies. The story follows the actions taken by the girls left behind on the school roof.

Your favorite cozy camping anime returns with a movie as the former members of the Outdoors Club get together again, this time to build a campsite! Reunite with Nadeshiko, Rin, Chiaki, Aoi, and Ena as they gather around the campfire once more with good food and good company.

Although μ'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 μ's members find in performing the most exciting live performance?