Jyu-Oh-Sei: Planet of the Beast King

Thor and his twin brother, Rai, are cast off to a forsaken planet by unknown masked men after witnessing the suspicious death of their parents. Given only a beam knife and a smelly satchel, they wander together in search of civilization on the primarily plant based world. They soon discover the plants have the advantage. Only the strong survive; the ones who throw away their humanity and become the beasts humans once were.

If you like this, try

Toward the Terra (TV) 81%

24 eps · 2007

Both strand a determined young man in a hostile system where survival demands he question his own humanity and loyalties.

ASTRA LOST IN SPACE 78%

12 eps · 2019

Swap the beast planet for open space, but you get the same disoriented survivors piecing together how to stay alive together.

No.6 77%

11 eps · 2011

You'll feel that same claustrophobic dread as a young man is stripped of everything and forced to fight just to keep his identity intact.

Origin: Spirits of the Past 75%

1 eps · 2006

Nature itself becomes an adversary here too, forcing its leads to decide what humanity is worth saving.