Six-Faced World

The Six-Faced World (六面世界 Roku-men Sekai) is a world that exists in a hexahedral form outside the three-dimensional world.

Structure
Of a total of six faces, each face is constituted of one world each ruled by one God -
 * The human world ruled by Human God
 * The demon world ruled by Demon God
 * The dragon world ruled by Dragon God
 * The beast world ruled by Beast God

The Six-Faced World was originally one world but was split into smaller worlds more than 100,000 years ago.
 * The ocean world ruled by Sea God
 * The sky world ruled by Sky God

History
These worlds were separated by barriers that were extremely hard to cross. No person in one world knew there exist multiple other worlds. Only the Gods and those strong enough to cross the barriers knew of the other worlds. This age was known as the Ancient Age of Gods.

Twenty-thousand to ten-thousand years prior to the main story, an incorrigibly evil and awfully powerful Dragon God was born. He destroyed the barriers separating the world, and along with his followers - known as the Five Dragon Commanders - crossed and began destroying the other worlds.

When only the human world was left, the Five Dragon Commanders retaliated against the Dragon God. The fight ended in a draw. The dragon world collapsed in the aftermath of the battle leaving only the human world.

Survivors from each destroyed worlds fled to the human world as a result.

Barren World
Aside from the six worlds there also exists another world at the centre of the cavity of the Six-Faced World known as the Barren World.

It is a pure white world of nothingness and is the path for moving to other worlds. It is also the channel for summoning and teleport magic.

Apparently, this pocket of space is where Hitogami exists.

Trivia

 * The world where the former self of Rudeus is from exists outside the Six-Faced World.

Note: This article is under construction and revision.