In the year 2089, eighty years after Space War I reshaped humanity and the Zentraedi, both species coexist peacefully on Earth. That harmony is shattered when a new alien civilization, the Marduk, arrives in our Solar System. While reporting on the inaugural clash between the U.N. Spacy and the Marduk armada, rookie SNN journalist Hibiki Kanzaki encounters Ishtar, an "Emulator" who amplifies the Marduk"s fighting power through song. Hibiki transports Ishtar back to Earth, hoping to instill in her the principles of life and culture. Joined by veteran Valkyrie ace Silvie Gena, Hibiki and Ishtar must devise a plan to prevent Earth from being annihilated in the hands of Marduk commander Ingues.