The story revolves around "the dark power generated by human evil thoughts - Yin and Yang evil thoughts". In the world of warrior knights, parasitic predatory creatures called "ghosts" live. They invade the human world with the purpose of reproducing their own kind, and satisfy their own hunger by possessing humans and preying on others. In order to fight against the invasion of Yin ghosts, mankind united as one and created the powerful "Emperor's Dragon Warrior Knights". These knights guard silently like shadows, vowing to stop the spread of Yin and Yang evil thoughts and protect mankind from being devoured by Yin ghosts.
