Even though Yamas are not youkai who reside in Gensokyo, they do appear in Gensokyo on rare occasions, so they will be given an introduction here.

In times past, when there were comparatively fewer humans, the cycle of spiritual transmigration operated with great reliability. The policy of crossing over seven times (plus 3 additional times)(*1) was carried out by the Ten Kings (*2). If the first judgement was succesful, then the cycles of spiritual transmigration would be as gratifying as the sweetest of desserts.

However, the number of humans increased little by little, and the number of judges proved unable to keep up, at which point the Ten Kings called upon the most powerful of Yamas of the day to reduce the number of pending trials as much as possible. And thus the shortage in personnel was resolved.

Additionally, Jizou (the bodhisvattas for children, travellers, and the underworld) from all over the country who were interested in serving as Yamas gathered, and the deceased who had died in proximity to a Jizou were entrusted with being judges.

Nearly all Yama are formerly old Jizou.

In present times, to address the issue of humans outnumbering judges, they formed "The Ministry of Right and Wrong" along with the shinigami and oni in Hell to take up the business of operations and oversight.

1: The number was originally seven times, but all of these "seven times" cases had problems, and so three additional judgements were implemented.

2: King Shinkou the Immovable, King Shoukou the Enlightened One, King Soutei the Wisest, King Fukan of Virtuous Conduct, King Enma the Merciful Savior, King Henjyou of the Future, King Taizan of Medicine and Healing, King Byoudou of Mercy and Compassion, King Toshi of Strength and Wisdom, and King Gotoutenrin of Limitless Light and Life make up the Ten Kings.

At the top of this organization, there presides 10 Yamas.(*3)

Below them are lesser judges and oni lords. Each and every judge also commands several shinigami, while each of the oni lords similarly commands a number of lesser oni.

Within this place, all lower ranks including lesser judges may consult with the Yamas.

First, for the spirits who have been brought by shinigami via Higan, they will be taken to the court of the lesser judge who has jurisdiction over where the spirit formerly lived.

Each trial has is presided by a single judge, who will pass judgement without heeding the testimony of the deceased (*4), and thus divide the souls towards Heaven, Hell or the Netherworld as the outcome dictates.

The oni lords will take charge as the souls fall down to Hell and will command the lesser oni in their torment of the deceased.

A wide array of torture devices could be used, but current economic conditions mean that many of these contraptions are in serious need of maintenance and repair.

The organization's primary sources of income are fares from those crossing the Sanzu River, as well as concession stands and food carts operating on the Road of Liminality.

3: When the number of those holding the top position start to become too numerous, what will the Ministry do then?

4: Dead men tell no tales.

Misdeeds committed while still living will be read loudly and clearly, the details and the severity will be considered, and the verdict will then be announced.

Once the verdict has been passed down, there is no chance of revoking or appealing the decision.

While this judgement will determine the final destination of the spirit, there are often lies (those who lie to the Yama have their tongues pulled out) spoken in the process, the Yama keeps an extensive archive at their side of past lies with which to threaten the deceased regarding risks and dangers.

To address the issue of an excess of deceased subjects, the judging proceeds in an assembly-line fashion, executed with extraordinary speed.

Two alternating shifts unceasingly pass down judgements, but in their free time, they enjoy a leisurely life in Higan.