Sanzu River

The Sanzu River is a place located in a world only accesable to certain monsters known as Ayakashi. The leader of them, Chimatsuri Dokoku is the captain of the ship that sails in the river along with his followers. The river is said to flood into the Earth when it is filled up with human cries and tears. The river is also acid to humans, but water to the demons.

Trivia

 * The water is acid to humans.
 * It is almost impossible for humans to survive in it.
 * Demons rule this river.
 * If humans were to enter this place, they would have to give up their life and turn into a cursed half human and half monster. Once they do that, the river is no longer acid but water.