During a concert by idol group Zwei Wing, an alien force known as the Noise attack the stage. Group members Tsubasa Kazanari and Kanade Amou suppress the attack using their Symphogear armor, but despite their best efforts, innocent bystander Hibiki Tachibana is fatally injured. Distraught and much to Tsubasa's dismay, Kanade sacrifices herself in the process to save Hibiki.

Two years later, Hibiki lives on. Tsubasa now fights alone. With the threat of the Noise increasing, Hibiki finds herself encountering the Noise once again but this time she is granted a chance to become attuned with the same Symphogear that Kanade wielded.

Bella Sway, a lunar cargo pilot and smuggler 100 years in the future, finds herself accused of a crime and marooned on Moonhaven, a utopian community set on a 500 square mile Garden of Eden built on the Moon to find solutions to the problems that will soon end civilization on Mother Earth.