It is the Correct Century, two millenniums after a devastating conflict which left the world broken. Earth is now mostly uninhabitable, and thus a remnant of humanity has resided on the Moon while the Earth and its few survivors recover.

In a future, decimated Earth after the discovery of a mysterious, alien spacecraft dubbed "Orphan". A group of researchers scour the planet for Orphan's disc plates using mecha called "Antibodies" in order to revive the craft, an event that would result in the utter destruction of all lifeforms on Earth. The protagonists Yu Isami and Hime Utsumiya must utilize a special Antibody called "Brain Powerd" to counter the Orphan plans and save humanity.

Loran Cehack is a spy sent from the moon to scout out Earth, whom they plan to invade. He grows to love Earth as his true home and, after discovering a giant mech from the dark ages, he begins to defend Earth in the war. The year is C.C. 2345. Growing tensions between the Earthrace and Moonrace have spiraled into an all out war. Mankind's only hope for peace lies with a young Moonrace boy named Loran Cehack, and his mysterious Turn-A Gundam, a relic of a dark history which nearly destroyed the Earth centuries ago. As a citizen of the moon, Loran is loyal to the beautiful Queen Dianna Soreil, all the while fighting to keep the technologically superior Moonrace at bay as the pre-industrial Earthrace tries desperately to catch up.

Rica wanting a fresh start leaves her friends and past life behind or at least that is what she thinks as trouble always seems to find her. Rica's looks into a ship that exploded and everyone who survived this disaster who comes in contact with her dies. Rica only chance of solving the mystery of the sunken ship is if she can locate a old friend of hers who just happened to be on that ship the night it blew up.