Set in 2055, four years after the events of Danball Senki W, LBXs have evolved into the world's premier hobby. The scene is now large enough to support professional leagues, allowing individuals to earn their entire livelihood as LBX players. Fourteen-year-old Arata arrives as a new transfer student at Kamui Daimon Integrated Academy, located on Kamui Island near Japan. Recognized as the most prestigious global institution for training LBX players and mechanics, the academy demands an exceptionally competitive entry requirement: candidates must be champions of at least three official tournaments. Together with his platoon members, Arata confronts rivals and uncovers the secrets hidden within the academy.