The year is 2199. The once blue and green planet Earth has been reduced to a radioactive desert wasteland by constant attacks by the hostile aliens from the planet Gamilus which force the remaining population underground. However, a friendly alien race from the planet Iscandar contacts the humans and gives them the blueprints to build a powerful space battleship capable of retrieving a device to clean the planet before humanity disappears. The United Nations Cosmo Navy - whose space fleets have been decimated by Gamilas forces - resurrects the long-sunken battleship Yamato and applies the alien technology to its interior, transforming it into the vessel for which the series is named: Space Battleship Yamato.