Long ago, the emperor's death triggered riots and civil wars that devastated Atlantia. When the young king Yaiba ascended the throne, treacherous rebels were executed to restore the peace the country once enjoyed. However, tainted by this radical act of governance, Atlantia remains shrouded in the shadow of oppressive rule. Tsurugi Tatewaki is a spirited teenager who grew up in the rural countryside with little memory of his birth parents. One day at home, he discovers a mysterious sword that transforms into a Battle Spirits card. When armed forces from Atlantia confront Tsurugi, aiming to seize his card, the secrets behind his past seemingly begin to unravel. Accompanied by a droid named Bringer, Tsurugi travels to the capital of Atlantia and encounters supposed warriors who wield similar swords. As his world is slowly turned upside down by the gradual emergence of greater mysteries, Tsurugi may have to question everything he knows, including his own judgment on what separates good from evil.