Netherworld

The **Netherworld** (隠世, *Kakuriyo*?) is the name given to the realm that serves as the "other side" of the human world; it is also referred to as **Mirrorrealm** (写世, *Utsushi-yo*?). This supernatural realm is the birthplace and home of the *aradama* as well as the place from which a *Toji* calls forth their supernatural combat abilities via their *okatana*.

## History

The Netherworld is, to put it simply, an alternative plane of existence that is far enough away that it cannot affect reality to any extent further than allowing for *aradama* to pass through the dimensional barrier that separates the two realms and for *Toji* to momentarily open a hole to access the other side for the purposes of using their powers. However, once every four hundred years, the two realms "collide" in the sense that they get close enough for living creatures and things to cross over to the other side. Normally, this cyclical exchange wouldn't have much of an effect, however, in the year 400 CE, *aradama* began crossing to reality. Fortunately, they went mostly unnoticed as that event was also among the quickest from which the Netherworld pulled away from Earth; cut off from their source of power, the few *aradama* that managed to cross were quickly purified by their own powerlessness. This event would have long-lasting effects on the human realm as many of the natural *okatana* crossed over during this time.

Following the shortest connection was the longest connection of 800 CE where *aradama* poured into the place that was and had the closest point of contact with the Netherworld, Japan, by the hundreds of thousands. Quickly, the peoples of Japan found themselves on the brink but just as quickly as they had, those few that possessed the natural *okatana* that had crossed over four centuries earlier have now found a use for them; the *aradama*'s numbers were quickly reduced but not before many of them left Japan and began expanding across the world (some *okatana* such as Joyeuse and Durandal serve as a sort of "beacon" for *aradama* and can be used as an anchor to open large-scale portals for which *aradama* can invade from during the four-hundred-year cycles)....

## Characteristics

The Netherworld is known to be composed of layers where each succeeding layer has a much stronger tendency to defy the conventional rules of time and space than the previous layer. There are at least seven known layers of the Netherworld, each corresponding to a level of *Jin'i*.

* **First Layer: Threshold and Shallows** (第1層・狭間と浅瀬, *Dai 1-sō: Hazama to Asase*?) - the shallowest layer of the Netherworld. This is the layer from which most low- to mid-class *aradama* are born in. This layer appears greyscale with the moon appearing in the sky at a much larger size than it should, covering half of the sky with its grey glow. Anything below the First Layer is colloquially referred to as the **Depths** (深淵, *Shinen*?).
* **Second Layer: Polychrome** (第2層・虹霓, *Dai 2-sō: Kōgei*?) - This layer appears prismatic and gives everything a rainbow-like glow, including *aradama*.
* **Third Layer: Borderland** (第3層・境界, *Dai 3-sō: Kyōkai*?) - This layer, as per its name, serves as the boundary between average *Toji* and talented *Toji* as surpassing this layer requires a certain level of control over Reiryoku and Reiatsu. Like the previous layer, everything has a prismatic glow, however, should a *Toji* not have sufficient control, they will find all of their items suspended in time save for their *okatana*.
* **Fourth Layer: Primordial Night** (第4層・原夜, *Dai 4-sō: Genya*?) - This layer appears to be completely and entirely black and devoid of natural color; even the moon in the sky which remains the same size as it has been in the previous layers is almost entirely black with blacklight being the only source of light. This makes it the most troublesome layer to fight *aradama* in...
* **Fifth Layer: Dawn** (第5層・暁, *Dai 5-sō: Akatsuki*?) - This layer has natural colors and appears to be trapped in perpetual dawn...
* **Sixth Layer: Noon** (第6層・真昼, *Dai 6-sō: Mahiru*?) - Like the previous layer, this layer has natural colors and appears to be trapped in perpetual midday...
* **Seventh Layer: Twilight** (第7層・黄昏, *Dai 7-sō: Tasogare*?) - The deepest layer ventured into so far, this layer has natural colors and appears to be trapped in early evening with the moon being the same size as it normally would be...