The narrative takes place during the Sengoku period. A ronin known as Nanashi (which translates to "nameless") rescues a young boy named Kotarou at an abandoned temple. Kotarou is without family, is being hunted by a mysterious Chinese militia organization, and employs Nanashi as his bodyguard. Among those chasing Kotarou is a man named Rarou, a skilled warrior with blond hair and blue eyes. He serves an old man called Byakuran and is a member of the Chinese militia. Unlike his fellow militia members, he does not serve any Emperor and simply wishes to fight strong opponents.