Facing summer homework is currently Hibiki Tachibana's toughest challenge, despite her many victories against formidable foes and countless lives she has saved. While her high school life is mundane, her experiences working with the military group S.O.N.G., and their use of ancient Symphogear armor, are anything but ordinary. Together with her team, Hibiki works to manage international conflicts and prevent disasters, all with the support of the United Nations. During a briefing for a mission, Hibiki uncovers the malevolent Bavarian Illuminati, an organization responsible for past disasters and havoc in Val Verde. Braving the risk of infiltrating one of their manufacturing plants, Hibiki and her comrades successfully free hundreds of enslaved individuals. However, the top members of the Bavarian Illuminati, alchemists Saint-Germain, Cagliostro, and Prelati, reveal themselves and announce a worldwide revolution led by their alchemical power. In order to protect thousands of lives, Hibiki and her team must face these transgressors in their most challenging and destructive battle yet.