Taking place centuries after its predecessor, Yamato 2520 follows the journey of the eighteenth starship bearing the name, as it faces off against the Seiren Federation. Amidst a planet heavily controlled by the Federation, a cluster of adolescent Earthlings stumble upon the old wreckage of the Earth Federation Battleship Yamato. Through absconding with its data disk, these teens utilize the Federation's own automated shipyards to build a new Yamato.