As the seventeen-year-old sole inheritor to the Tsukioka family and their bankrupt weapons company, the game introduces the player to a world where all manned space exploration projects have been put on hold indefinitely due to a material called "Space Nectar" that poisons and kills any organic life in space. Earth is safe because of its atmosphere, but it seems that humanity is doomed to an isolated existence.
When machines known as Volgara begin destroying the Earth, the player must pilot the only weapon on Earth capable of standing against the invaders. Along the way, lives will be changed, history will be made, and the origins of the Volgara will be revealed.