A year ago, a strange ritual happened to Yatogami Hikaru, causing him to witness the deaths of many people as well as the birth of beings known as Phantoms. After that ritual, Hikaru met Soma Haruto, the Kamen Rider Wizard, and was given the WizarDriver by him to become Kamen Rider and fight. In the present time, Kazanari Tsubasa and Amou Kanade, the idol duo known as Zwei Wing, use their songs to power an ancient weapon known as "Symphogear" against a race deadly alien, called "Noise". While the public knew of Noise's existence, knowledge of the Symphogears remained secret.
One day, Yatogami Hikaru, a disciple of Haruto, attended a concert with his best friend, Tachibana Hibiki. The concert was attacked by Noise causing many people to die. In that situation, Hikaru transformed into Kamen Rider Wizard to join Kanade and Tsubasa to fight Noise. While they were fighting Noise, Kanade was about to sacrifice herself to protect Hibiki, who was accidentally dragged into their fight. However, the Wizard stopped her in time, but that also left Tsubasa devastated and a fragment of Kanade embedded in Hibiki.
Two years later, while Hikaru was on his way to hunt down the Phantoms and protect the Gate, the magical beings in their bodies were hunted down by the Phantoms. He met Hibiki and the two were dragged into an attack by Noise again. In that situation, from Hibiki's chest wound, the Relic of the depths of her body awakened and gave her the power of Symphogear to fight.