Shunta Mogami adores the Battle Spirits game. One day a radiant beam from a Battle Spirits card carries him into Spirits World, the birthplace of all Battle Spirits. There he encounters a girl named Eto who says she summoned him to stop the revived Evil God-King from destroying Spirits World, a deity once plotted its ruin before being defeated and sealed. Joined by the self-assured green-deck‑user Yoku Albatrosa, who also arrived from another realm, Shunta embarks on a quest to locate the twelve God-Kings whose combined might originally sealed the Evil God-King in hopes of restoring balance to their world.