The Blue Forest (雨の森, Ame No Mori, Rainy Forest) is an area accessible from Garden World.
The area uses the same sprites used for Garden World, containing blue trees and defined blue grass blades that make a noise when stepped on. Around its Garden World entrance is a mesh gate. Sometimes the area will be considerably darker and it will be raining, and the music will not be present in favor of the ambient noise of what seems to be a nearby animal.
If you go left from the entrance, you will come across a crossroads with a strange yellow and green fish in the center- you will appear next to this fish if you enter from the Butterfly Forest. If you go straight across, there is an easel with a canvas on it. This will transport you to the Art Gallery. On the road leading up, there is a tree with dark yellow bark as opposed to orange which will transport you to the Exhibition. The road leading down has a moving Mantis NPC, which takes you to a classroom in the School when you interact with it.
If you go right from the entrance, you will come across a small boy sitting on a bench next to a clock similar to the one at the Nexus entrance to Garden World. If you sit next to him, he looks at you.
When the boy is not present, an odd snake-like monster can be found in the lower right clearing and can be reached by a path south of the bench. When interacted with, it will make a strange sound.
Nexus → Garden World → Blue Forest
Before 0.099d, the hole leading to garden world was a connection to The Hand Hub, from where the blue forest was previously accessible.