In 2199, after five years of attacks by an alien race known as Gamilas which rendered the surface of the Earth uninhabitable and forcing humanity to evacuate underground, the Earth Defense Force launches a counter-offensive near Mars. The fleet's weapons are no match for the Gamilas, who easily wipe out much of the force. During the battle, EDF captain Mamoru Kodai volunteers to use his damaged ship, the destroyer ''Yukikaze'', as a shield to cover Captain Jyuzo Okita's battleship, allowing his escape. Mamoru's ship is destroyed.