Yutopia

(FYI, this place is very old and was mostly focused on being as self-indulgent as possible since it comforted me for a while, so go easy on me here also if you can.)

Yutopia is a world in the realm of fiction (a middle plane more real than the name may imply, only more subtle and flexible than the ones below) but with residents that are able to visit the material realm with ease. However, while that is the case, they cannot simply bring their magic and wonders with them, and instead turn into either humans or normal animals (depending on what they were in Yutopia) when crossing to the other realm. Caelestis created the world with the assistance of Sozo, who was to look after the realm afterwards. While created more as a test of power than anything, it ended up quite elaborately made to be as much of a paradise as possible. The incovenient, excessively unpleasant aspects of life were tossed away, and the more interesting ones allowed to remain.

While the residents can freely enter and leave the material realm, they cannot so easily stay for a long period of time. Their auras conflict with that of the material plane's. It isn't all that noticeable at first, but the longer they reside there, the harder a time they have functioning, gradually sinking into a deep despair.