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. [Written by MAL Rewrite]

Three months after a Lunar Attack which nearly caused Earth's destruction, Hibiki Tachibana, Tsubasa Kazanari, and Chris Yukine continue to fight the Noise—a mysterious alien threat—using powerful armor known as Symphogear. After defending an American convoy from a Noise attack, Hibiki and Chris race toward the Queens of Music concert hall to attend one of Tsubasa's concerts. Meanwhile, Tsubasa and rising international superstar Maria Cadenzavna Eve deliver an amazing performance that is broadcast throughout the entire world. Just as the concert is about to conclude, a group of Noise suddenly appear, plunging the hall into chaos. Amidst the panic, Maria declares war against the world as the successor of Finé—Chris' former mistress—and her allies Kirika Akatsuki and Shirabe Tsukuyomi reveal Symphogear powers of their own. After initiating a skirmish with Tsubasa and her teammates, they retreat mysteriously, leaving the three friends bewildered as to what their true intentions could be. [Written by MAL Rewrite]

Following the events of Senki Zesshou Symphogear G, Hibiki Tachibana, Tsubasa Kazanari, and Chris Yukine continue to operate under the command of Genjuurou Kazanari. Meanwhile, Maria Cadenzavna Eve, Kirika Akatsuki, and Shirabe Tsukuyomi are taken into protective custody. With peace restored, everyone returns to their daily lives; however, the appearance of the alchemist Carol Malus Dienheim and her subordinates—the "Autoscorers"—threatens to draw everyone back into a conflict. Armed with a strange and magical power, Carol wishes to initiate the apocalypse and bring destruction to the world... and she is willing to sacrifice everything to do so. Against this mysterious new foe, the six Symphogear wielders must rise to the challenge in order to protect what they hold dear. However, will Carol and her Autoscorers prove to be too much to handle in this fight to protect the fate of the world? [Written by MAL Rewrite]

Hibiki Tachibana has defeated many powerful enemies, saved countless innocent lives, and escaped from numerous desperate situations, but she is currently finding herself unable to escape from her most desperate situation yet—summer homework! Although her high school life is relatively unremarkable, her career as a member of the military organization S.O.N.G. is anything but. Using powerful, ancient armor known as Symphogear, Hibiki and her teammates work with the United Nations to deal with international disputes and disasters. During a mission briefing at headquarters, Hibiki is made aware of a mysterious organization known as the Bavarian Illuminati, who has been responsible for several major disasters in the past and currently operate in the war-torn country Val Verde. Together, Hibiki and her team infiltrate one of the Bavarian Illuminati's manufacturing plants and free hundreds of slaves. Exposed, alchemists Saint-Germain, Cagliostro, and Prelati reveal themselves as the organization's top brass, and—using alchemical powers—declare a global revolution while sacrificing thousands of lives. Faced with yet another threat to the world's survival, Hibiki and her allies must confront the Bavarian Illuminati in their most difficult and destructive battle yet. [Written by MAL Rewrite]