
The Monster World is a dimensional world for ayashi of different races and in it lies the school, Yokai Academy. Monsters are hidden in this world from the human race to not know about their existence, but if any monster goes to the the Human World they'd remain in their human forms so they don't reveal their true natures to be on the safe side.
Generally populated by Yokai. The only humans that came across into the Monster World are Tsukune Aono, Hokuto Kaneshiro, and Kyōko Aono.