Three hundred years ago, the known world consisted of nine continents spread across a vast ocean. Ohka was the center of this world, ruled by five martial-art houses, until Sema, one of the continents, threatened their rule. Once considered an outcast, Shinbu returns home and defends his clan, the Gate of Seiryu. After learning that he and a girl name Suirin are the only two living clan members left, Shinbu joins her on a journey to defend their clan and return the balance of powers in Okha.