The story describes a world called Brestier, where a huge organization called Gildo dominates aviation technology in an attempt to use its powerful technological power to control the world. Anatole and Duxis, the two major countries of the world, were at war. In order to compete for supremacy, both countries commissioned Gildo to design aerial warships, and Gildo provided the engine. Two pilots, Klaus Walker and Ravi Haight, who own an Oneship, operate the air transport business. The two men saved a young girl named Elvis Hamilton in an aircraft accident and sent her to the aerial battleship Sievana, thus involved in a battle between the survival of the world.