Haru Shirogane is a weak-willed individual who is often tormented, whereas Taiga has gone from across the sea with the aspirations of becoming the world's strongest man. The two meet up with Shun Kamiya, the Minato Tribe's strongest XB (Extreme Baseball) player and commander, one night. Each of the Tribes spread around Neo-Tokyo is set to confront a great challenge when they gather. On the instructions of the King of Neo-Tokyo, the Chiyoda Tribe's "Houtenshin," commanded by the enigmatic Ojiro Otori, has begun to seize control of all of the country's tribes. The Minato Tribe is going to be engulfed in their terrible claws...