Mars

Mars is the fourth planet in the solar system known for the red dust covering the surface giving it the nickname, the Red Planet. It has been the subject for much debate on habitability for years due to the presence of water. In MazinSaga it became the main setting after Earth ravaged by Z. The planet has a gravity 1/3 of Earth's with people who directly come from Earth getting higher strength and stamina.

History
Mars was once home to a race of lifeforms similar to humans with God Kaiser Hell being the only survivor. Eventually he uncovered the gates of Hell, unleashing demons that God Kaiser Hell converted into his Bio-Beasts. When Earth was ravaged by the bio-armor Z, the survivors immigrated to Mars building a colony called FUJI. Hell, not wanting to lose what he believes is rightfully his declared war on FUJI. Soon an alien force also comes closer to the red planet with the intent of domination.

Trivia

 * The Gates of Hell on Mars predates the concept featured in the 1993 first-person shooter game, Doom.