McDonald, the son of the "Red Devil" Mai Lin, grew up on Earth. He followed in his father's footsteps and was determined to find the "Rainbow Sea" that was regarded as a lie. He relied on magical powers to break through the restricted area set by the evil organization "Galaxy Eyes" and met Gudong, the king of the small planet. The subjects were frightened by the alchemist's conspiracy and turned Gudong into a rabbit, but he still fell into the trap set by the alchemist. McDonald bravely defeated the alchemist and flew to the Rainbow Sea with Gudong in a spaceship, but the route was closed by the Interstellar Alliance, so they had to cross the death route "Devil's Footprints". After going through hardships, they crossed the ice and snow maze with the help of the Uranus natives, defeated powerful enemies, and entered the snow meteor where the voyagers were killed. Just when victory was in sight, a greater danger appeared. The space pirates kidnapped Gudong. Among the pirates, there was also the heroic young man Milong with superb kung fu. Can McDonald continue to move forward...