Two months have passed since a zombie epidemic overran the world. In the midst of this chaos, three high school girls wearing sailor uniforms live a surprisingly ordinary school life at Fujimi Girls High School, a refuge for surviving students. Maiko Inui is a transfer student who arrives at the school with a dream of becoming an idol. Despite the desperate situation, she begins to deepen her friendships with her classmates Momoka Takizawa and Mutsumi Oyamada.

The girls discover a bizarre phenomenon that becomes key to their survival: when specific music plays from a radio, zombies stop their attacks and begin to dance. This music temporarily protects humans from the zombies, but the source of the broadcast remains a mystery. As the story unfolds, Maiko and her friends encounter increasingly strange threats, including a massive forty-five-meter tall fashionably dressed zombie.

Seeking answers, the girls set out to find other survivors. Through a mysterious girl named Arle, they learn that zombies possess emotions and can cry. Their quest leads them toward Takurou, a survivor who happens to be Maikos first love, but their path is blocked by a massive horde of relay zombies and companions begin to fall one by one. The search for the music source intensifies, and Maiko eventually obtains a CD containing the seventh song, a prize that comes at the cost of her memories.

When Maiko and Momoka finally return to Fujimi Girls High School, they find the atmosphere drastically changed. A student named Nanako has taken control, and the school is spiraling toward collapse as their friends fall one after another, leading to a final confrontation.