The story is about a world called Brestir, where a huge organization called "Gildo" monopolizes aviation technology and attempts to use its powerful technological power to control the world. The two major countries in this world, Anatoly and Dusis, are at war. In order to compete for hegemony, both countries commissioned Gildo to design an aerial battleship, and Gildo provided the engine. Two pilots, Klaus Walker and Ravi Hite, who own a Oneship, run an air transport business. The two rescued a girl named Elvis Hamilton in an aircraft accident and sent her to the aerial battleship Sievana, thus being involved in a war that concerns the survival of the world...