Portriss World is known as the home planet where robotic beings called Portriss live in peace. But the harmony was disrupted when the sudden presence of a dictator named Dark Portriss plans to take over the world. Now it's up to the Portriss Knights Karot, Duke, brothers Dig Dug, and Yuma, a mysterious human boy, to battle the evil forces and maintain peace throughout the Portriss World.