Tenchoku

Tenchoku (天勅, Mandate of Heaven) is Heaven's consecration of the new ruler's throne. On this type of occasion people typically wear black to celebrate an auspicious time. The Tenchoku is received at the Untei Gate on Mt. Hou.

Overview
Once a ruler has been chosen by a kirin, the ruler must accept a mandate from heaven (the tenchoku) before formally ascending the throne of their kingdom. The tenchoku essentially outlines the three greatest transgressions a ruler cannot commit. Should a ruler commit any of the three transgressions, heaven will make clear that a violation has occured, often with great consequences. When Juntei, a previous ruler of Sai, sent his royal army into Han to aid refugees, he and his kirin Sairin were instantly struck dead for violating the third precept. In contrast, the decision for Shoryu to send royal army of En into Kei did not produce the same result as heaven likely accepted that the army was legitimized by the acceptance of Youko's agreement to allow the army to enter Kei to liberate the kingdom from the control from a pretender to the throne.
 * The monarch must not violate the heavenly precepts and deny the way of righteousness.
 * The ruler cannot reject the Mandate of Heaven and elect for death over royal responsibility.
 * The monarch must not invade another kingdom, even with the intention of preventing war.

Mandate of Heaven
In the The Twelve Kingdoms: Sea of Wind, the mandate is written as follows. "'In the beginning, there were nine provinces and four tribes. The common people knew not the light of reason; and though they knew of Heaven's Providence, they mocked it, and to the gods paid no obeisance. They disdained the laws of Heaven and Earth, shunned virtue, and made light of the law. Smoke rode upon the wind in place of clouds, and war fires reduced vast territories to ash. Men and horses died, and their blood cut a channel in the earth that became a great river." "The Emperor of Heaven was saddened by this, and he tried to show the people the Way and give them reason, yet men succumbed instead to the voice of vice, seeking only pleasure in their short lives. And therefore, the Emperor, in his grief, made a proclamation:" "'I will flatten the nine provinces and four tribes, returning the world to the way it was in ancient times; and with reason as my plow, I shall remake Heaven and Earth in the image of the ropes and records that are the law.'" "Then, the world was renewed, and the Emperor cut thirteen kingdoms from the harrowed ground; in the centermost of these, he made the Koukai and the Five Mountains, and he set the Dowager of the West to protect this place as a sacred land." "To each of the remaining twelve kingdoms, he gave a king--and to each king, he gave a stately branch around which to build the Order of Law." "Around each branch was coiled a serpent. The kings unwound these and held them up to support the heavens." "Upon each each branch grew three fruits: One fruit fell and became a jeweled throne, another fell to become the fertile land, and the third fell to become the kingdom's people." "Then, each branch changed to become a jeweled brush. With these brushes was written the beginning of the world." "In the first of the Great Ropes, it is written: The land must be ruled with virtue." "Let not the master's heavy hand bring fear or deprivation. Do not treat the people with cruelty, nor grow fond of the taste of war. Do not overburden the people taxes or decrees. Do not sacrifice the people, nor sell them as goods, nor horde public land, nor allow any other to commit such acts within the boarders of your realm. Follow the Way, and lay virtue upon virtue. The kingdom knows happiness only through the safety and wellbeing of all its people....'"