Jyu-Oh-Sei - S01

After their parents are murdered, 11-year-old twin brothers Thor and Rai Klein are sent away from their home planet. They wake up on the terraformed planet Chimaera, where carnivorous plants rule and the few humans living there are split into four groups called "Rings." They soon meet a young man named Zagi, and the twins learn that only the "Jyu Oh Sei," the one who conquers all four Rings, is allowed to leave the planet. Driven by the wish to go home and find out the truth behind his parents' death, Thor decides to survive in Chimaera's harsh, merciless environment. But he quickly learns there is more to this strange ecosystem than it seems. As Thor gets caught up in the politics entangling the Rings, he uncovers more about his parents' murder and, in the end, humanity's fate as a whole.