The inhabitants of the planet Roha are concerned that the two developing worlds of Earth and Saturn may soon engage in armed conflict and threaten the peace of the galaxy. They decide to choose a team of one human and one robot to represent each planet in a contest of survival on the planet Moribund. Astroboy is in the middle of breaking up a robbery, when he and the thief (Mr Scrap) are taken away by "Magic Rings" to face off with Alpheta and her robot Omegum. The winners' planet will be spared and the losers' planet destroyed.