Unlike his other worlds which almost always are set in a dark forest at night (sans Advent: Path of the Highest, which is set in the day-time.) this world is an open plain stuck in an endless daytime, which expands out into forever. In the center is the World Tree which regulates the chakra needed to control and maintain the worlds. This tree and Naoto are one in the same as the tree cannot exist if he is slain and his worlds are fed by him through the tree.