When Tadashi Daiba's father is murdered by invaders known as the Mazon, he becomes frustrated in the face of the Earth government's flippant attitude. Landing himself in prison, Tadashi finds himself invited aboard the battleship Arcadia, controlled by none other than the legendary Captain Herlock. Joining his crew on their journey through space, Tadashi's future will lead him to confront not only the Mazon, but the many other forces across the universe threatening humanity's very existence.