In the not so distant future much of the earth has been submerged under sea or destroyed by earth quakes. At the center of the turmoil is the mysterious Orphan. Orphan may or may not be the original cause of the cataclysms. Orphans goal is to raise a ship hidden deep beneath the sea to the surface, doing so however would result in the destruction of all humans except for the small number which are lotal to Orphan.
Orphan's agents pilot mysterious mehca know as Grand Cheres, and search the world for mysterios, giant disks which occasionally appear, flying at high speeds and wrecking much of the country side, or cities, when they hit the ground. After a dlying disc almost kills Hime a Brain Powerd is born from the disc. Brain Powerds are another type of Mecha, similar to but not the same as Grand Cheres.
Hime becomes the Brain Powerd's pilot, forming a symbiotic relationship with the living mech and joins an International Organization dedicated to stopping Orphan, or at the very least saving humanity should Orphan succeed.