In the future, humanity has achieved a vast starfaring civilization, but is slowly and steadily succumbing to ennui or despair, often due to defeat and subjugation by a foreign invader. Rising against the general apathy, Harlock denies defeat and leads an outlaw crew aboard his starship Arcadia to undertake daring raids against Earth's oppressors. Their primary oppressors are the Mazone, a race of organic plant-based alien women who explored Earth in the mythic past and are now back to reclaim it.