White Fern World is an area accessible from both the Apartments and the White Mushroom Field.
Features
The area largely just contains a scribbled white floor with various objects in the foreground. It also snows a lot in this area.
From the two main entrances, there is a long path with multi-colored faces along it. When you reach the end, you will be transported to a small sub-area containing a purple character that turns ghostly when
you step inside the same area as him. If you step inside the middle square on your left, it will transport you to a larger area with gray buds on stalks and fern-like plants scattered around. In this part of the world there is a small building surrounded by the gray plants with eyeballs popping out of them. Going into the building will send you up to the top of the building and overlooking a strange scene. Interacting with the hankerchief here will give you the Tissue effect.
There is also an entrance from the Power Plant that leads you to a path with monsters resembling the headless eyeball monsters from Yume Nikki. Going to the end of this path will simply result in you starting in the area containing the Tissue building.