Onyx Tile World (大理石世界, Dairiseki Sekai, Marble World) is one of the main worlds accessible from the Nexus.
Features
As its name suggests, the world is mainly filled with gray tiles and pink and green tube-like objects with little else in terms of atmosphere.
There is a pink, worm like object in this area that changes color depending on the number of times Urotsuki has gone to sleep. When this happens, many chasers appear.
At the end of a long pathway, there is a pink-purple doorway leading to a building with a Robot Guard at the front desk. If you take the elevator up and enter the office on the next floor, you will find a fairy in a cage which gives you the Fairy effect.