Kou

The first kingdom that Youko Nakajima sets foot in, the kingdom of Kou neighbours the kingdoms of Kei and Sou and is known as the one of the four "middle" kingdoms. Its capital is in Gousou (Place Where the Frost is Proud) and the royal Jadegrove (Suikou) Palace is located on the peak of the nearby Mount Gosou. The title of Naze-King is granted to the King of Kou; the most recent king has ruled for fifty years.

When Youko arrives in Kou, the Naze-King attempts to eliminate her before she can claim the throne and he secretly supports the imposter king, Joyei. In the anime, the King of Kou meets his eventual downfall when Kourin sacrifices herself to protect Youko from the Naze-King's sword; with the death of his kirin, the king dies two months later. He is posthumously known as Saku-ou (the Foolish King). His two children decide to end their contracts of immortality to live among the common people, trying to eke out a living from the poor land and refusing Youko's offer to live in Kei. Following Kourin’s death, a new ranka for Kou began to grow on Mount Hou.

During Saku-ou's reign, Kou's fields became increasingly barren and youma attacks are more common. As one of the eastern kingdoms, Kou receives quite a few kaikyaku; however, unlike in En or Kei, they are rarely welcomed. Because kaikyaku often come after a shoku, people have held superstitious beliefs that kaikyaku are bad luck and responsible for the disasters which come from shoku; often, they are either imprisoned or executed. Both kaikyaku and hanjyuu were deemed unnatural by Saku-ou and were not allowed education, employment, or social services.

Provinces

 * Jun Province
 * Ki Province
 * Nei Province

Districts

 * Fuyou District

Prefectures

 * Rokou Prefecture

Counties

 * Anyou County
 * Hokuryou County
 * Shin County

Cities

 * Agan
 * Fugou
 * Goryou
 * Goso
 * Gousou
 * Hairou
 * Hokuryou
 * Kahoku
 * Kasai
 * Takkyuu