Mayohiga (InstanceTopic, 7)
From Compile Worlds
Mayohiga (which really looks and sounds like it should be called Mahiyoga) is a place in Gensokyo where Yukari, Ran and Chen live.
Apparently, items from Mayohiga give you good fortune if you take them home. But you can't leave once you wander in. Unless Chen yells at you. ...Eh?