The year is 1999. The Idelians, whose colony-ship has been wandering space for tens of thousands of years, are nearing exhaustion. Their sole hope is to settle on the nearest habitable planet, Earth. Soon after their arrival in orbit, they launch an invasion, landing a large attack force in the Alps.
The Special Armored Battalion Dorvack. Under the command of Colonel Takagi, Masato Mugen, Pierre Bonaparte and Louise Oberon fight to defeat the invaders. They are equipped with special variable mecha that are able to convert from rugged all-terrain vehicles to humanoid forms.