What makes a man good or evil? Is it his political power, swordsmanship, or loyalty to his lord? With Japan's second shogunate collapsing, the country falls into chaos known as the Sengoku period or Warring States era. The feudal holdings are ravaged by civil wars, and a man can rise up in society by killing his superiors. Amidst this violent landscape, a ronin without a name encounters a young boy named Kotarou, his faithful dog, and a group of Chinese assassins seeking the boy for some mysterious ritual that grants immortality. Finding echoes of his own past in the child, the ronin decides to become Kotarou's protector. But can he truly safeguard the boy from the Ming Dynasty and their ruthless blonde mercenary, Luo-Lang?