Tsubasa Kazanari and Kanade Amou—the idol duo known as Zwei Wing—use their songs to power ancient weapons known as "symphogears" to combat a deadly alien race called the "Noise." While the general public is aware of the Noise's existence, knowledge of the symphogears are kept a secret. When the Noise attack one of Zwei Wing's concerts, Kanade sacrifices herself to protect a young girl named Hibiki Tachibana, leaving Tsubasa devastated and a fragment of her symphogear embedded within Hibiki. Two years pass and Hibiki is once again dragged into a Noise attack. While rescuing a young girl who has been left behind during the evacuation, she awakens the power of Kanade's symphogear lying within her. Although Tsubasa still grieves over the loss of Kanade, both girls must now learn to work together using their powers to defend humanity against the Noise. After the frontier incident, everyone who knew the circumstances believed the Noise were gone and the pain they caused was at an end. But a new conflict approached unseen. In the Yokohama Harbor Oosan-bashi Pier, a new pattern is detected that is similar to the Noise. A combat group wielding mysterious technology stands in the way of Hibiki and the others. When she hears of this enemy of unprecedented strength, Tsubasa hurries back home from England. But the Symphogear users see no opening to counterattack and are forced into a difficult fight. In this situation of extreme disparity, the battle for the song that will end the world begins.