In the Sengoku period, a rounin called  Nanashi (meaning  nameless) saves a young boy  Kotarou and his dog  Tobimaru at an abandoned temple. Kotarou has no family, is pursued by a mysterious militia organization from China and hires Nanashi as his bodyguard. Among the pursuers is a man called  Rarou, a very skilled warrior with blond hair and blue eyes. He obeys an old man called  Byakuran and is a member of the Chinese militia. Unlike his companions in the militia, he is not serving any Emperor and just wants to fight with the strong.