Jokaku (舒覚) was Youko Nakajima's immediate predescessor as the ruler of Kei. After her death, she was posthumously known as You-ou (予王, the Prophet-King). As Keiki's first monarch, her failure has a lingering impression on Keiki, who finds himself comparing Youko and Jokaku as Youko attempts to assert herself as the new monarch of Kei.
Born into the Jou family, Joukaku's former life was that of an elder daughter of a merchant of a kimono shop. Informally known as "Onko," she had only wanted to live a quiet life with a husband and children. Keiki recalls her as a woman with a kind and thoughtful disposition, but was extremely shy and underconfident. Though Keiki recognized that she would not be a successful ruler, he could not deny the revelation that she was to be the next queen of Kei.
However, 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 Her sister, Joei, encouraged Jokaku's withdrawn behavior and used Jokaku's affection for her in order to gain power in court.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. Her reign ended after six years and became known as Yousei (予青), the Era of the Blue Prophet. Jokaku's short reign became the shortest of three successively short reigns by three female rulers, adding to Youko's burden of asserting herself among her ministers.
Following the Prophet's death, Keiki searched for the next ruler of Kei and found Youko Nakajima, a taika. However, during his absence, Joei, aided by the king of Kou, came forth and claimed the title of monarch of Kei.