It's survival of the fittest. To survive, it's kill or be killed. Two young twins, Thor and Rai, live on the space colony Juno. One day they arrive home to discover that their parents have been murdered, and suddenly for unknown reasons they themselves are kidnapped and abandoned on Chimera, a penal colony. Chimera, also known as the "Planet of the Beast King" (Jyu Oh Sei), is a harsh world which is populated with giant carnivorous plants and sparse groups of criminals and outcasts. Thor and Rai are faced with a desperate fight for survival by whatever means necessary whilst they attempt to get to the bottom of the conspiracy that has ruined their lives...