AD 2436. Thor and Rai are twins who’ve been raised in the space colony Yuno, of the Vulcan Federation Government, 150 light-years away from Earth. Their parents are killed in a horrific manner, and they are sent to the “Ju Oh Sei”, or the Planet of Beasts, by the Federation Army. Ju Oh Sei, whose actual name is Chimera, is a prison planet for ferocious criminals where only the most ferocious 'beasts' can survive.
There are 4 communities on the planet, Blanc Ring, Sun Ring, Nights Ring, and Ocle Ring. They are divided by their skin colours.
Ju Oh, the King of Beasts, is the top dog chosen from each community, and they rule Chimera as kings. In order to avenge the murder of their parents, and to discover the truth behind that event, Thor aims for the position of Ju Oh.
Jyu-Oh-Sei (獣王星, Jū Ō Sei?, lit. Planet of the Beast King) is a manga series created by Natsumi Itsuki. An 11-episode anime adaptation was animated by BONES and premiered April 13, 2006 in Japan as part of Fuji TV's Noitamina programming block.
On May 2, 2009, the series made its North American television debut on the FUNimation Channel.