Jokaku was Youko Nakajima's immediate predescessor as the ruler of Kei. After her death, she was posthumously known as You-ou, the Prophet-King.

Jokaku's inability to control of the court resulted in her withdrawal into the Inner Palace and refused to involve herself in governing Kei. She became susceptible to flattery and elaborate gifts from her advisors - including a small village of elderly people and children that she would frequent in order to teach children embroidery and poetry, reflecting the ideal life she wanted; this gift was from Gahou, who Jokaku rewarded by making him the governor of Wa. Her sister, Joei, encouraged Jokaku's withdrawn behavior and used Jokaku's affection for her in order to gain power in court.

In hopes of improving Keiki's relationship with Jokaku, the Genkun Gyokuyo on Mount Hou, arranged for Keiki to help Taiki and learn to be more sensitive to the feelings of others. However, Keiki's awkward kindness caused Jokaku to fall in love with him. Out of jealousy, she banned all the women from the palace and then the entire country, so that no else could take advantage of Keiki's kindness.

Jokaku's tyranny continued until Keiki fell ill with shitsudou. Grief-striken, Jokaku realized that she had lost the way and ascended Mount Hou to abdicate her throne and end her life in order to save Keiki.
(Source: wikia)