A young boy named Jiro finds his mother and sister murdered in his home. Falsely accused of the crime, he flees from his village and meets a priest named Tenkai, who has him kill a rogue ninja named Tarouza. After fulfilling that task, Jiro undergoes training to become a master assassin. Many years later, Jiro finds out that he was an orphan and his real father was Tarouza, who had worked for Tenkai until he aborted...