In a world ravaged by natural disasters, much of the earth lies submerged under the sea or in ruins. The enigmatic figure known as Orphan presides over the chaos, potentially responsible for the devastation. Orphan's objective is to retrieve an elusive submerged ship, even if it means sacrificing all but a select few loyal to them. Orphan dispatches their agents, who operate the enigmatic Grand Cheres, in search of enormous disks that sporadically appear and wreak havoc upon impact. When one of these disks nearly kills Hime, a Brain Powerd emerges from it. Brain Powerds are a kind of mecha akin to the Grand Cheres but distinct from them. Hime, now linked with the sentient mecha, becomes its pilot and joins forces with an international organization aiming to thwart Orphan's plan to destroy humanity. Saving as many lives as possible is their primary objective.