Joei is the younger sister of the previous queen of Kei, Jokaku, daughter of the Jou family. Unlike her sister, she is confident and believes herself to be qualified to be a monarch; as a result, she resents that Jokaku was chosen to be the queen instead. When Jokaku became increasingly withdrawn, Joei encouraged this attitude and took advantage of her sister's affection for her in order to gain power within the court. When Jokaku dies, Joei attempts to take control of Kei as its new monarch while Keiki disappeared from Kei in order to find the next king of Kei.

(Source: wikia)