In the near future, mankind has abandoned the Earth, which has become unsuitable for human life. Human beings began to build space stations. Thanks to the new space suits invented by professor Toujou, which allowed unrestricted presence in the space, humans could eventually spread over the galaxy. The planet Charon became the new center of science and culture. But soon, a mysterious organization known as "Giras" appeared on the stage. Their troops attempted to invade Charon, and at the same time professor Toujou has gone missing. His niece Lisa was determined to continue his research and discover his whereabouts; but was herself kidnapped by the Giras. Two of her friends, Kyouhei and Kamui, decided to lead an assault on a Giras stronghold and rescue Lisa...