Earth initiated space colonization by establishing the Next Colonies. Next subsequently rebelled and formed the Next Government. The rebellion escalated into war, prompting the multi-purpose Metal Vehicles (MVs) to be converted for combat. Meanwhile, Terra, an Earth Rebellion faction, began causing further trouble for Earth. Currently, a mysterious MV-like entity, S.A.C (abbreviated as "S"), is at large, and Next seeks it to secure victory in the war. Hal, Terra's psychic leader, has been sensing "S" and wishes to learn more about its power. The future of these three groups will depend on a group of outlaws residing on the abandoned Next 7 colony, although no one is aware of this yet...