Since every child in the world is born with creativity and playfulness, Eden was created alongside Rex, the host. Eden was born as a mirage of Rex, who would inspire them to live their lives, pursue their dreams, and be creative. They would transport Rex into their own imagination while they slept or dreamed, a place where anything was possible. Everything was possible with just their imaginations, and the worlds would constantly be lively, colorful, and joyful.

However, as a fresh illusion of Rex emerged, Eden's hold over the mindscape began to wane, and they themselves began to vanish, lost and imprisoned in the mind. The host abandoned them and sent them into a blank space that was all white. They waited, questioning themselves and having nowhere else to go. They came upon a sphere of glowing papers one day while aimlessly meandering through the emptiness; it was as though the papers were a hub for several different worlds. They harvested the magic from the bubble, shrunk the ethereal papers to the size of a poker card, and created a plethora of items, towns, cities, and things—aside from living things. They evolved into a creation endowed with creative ability. They then began to re-create the imagination they were once familiar with.

When the shield between fantasy and reality was broken, Eden appeared in a room, with the host sobbing hopeless alone as their colors fade away and REM slyly grinning in the corner..