Hourin was the kirin of the kingdom of Hou during the reign of Chuutatsu, the father of Shoukei; Chuutatsu is the second king she had chosen. When the king becomes increasingly fanatic about enacting harsh laws in hopes of ensuring his people become righteous, Hourin beseeched him to be more lenient. Her efforts unfortunately pushed further towards his belief that he needed even more austere measures and when Hourin has contracted shitsudou, Chuutatsu fails to see he has lost the way and continues to ruthlessly punish his people. The sickly Hourin is eventually confined in the Inner Palace with Chuutatsu's wife, Kaka, and his daughter, Shoukei. When Gekkei, the governor of the province of Kei, leads the rebellion to dispose of Chuutatsu, he arrives in the Inner Palace with his supporters and alarmed with how severe her shitsudou has become. Hourin willingly submits to being executed when Gekkei's supporters demand retribution for Hourin having selected two poor kings. (Source: wikia)
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 When Jokaku became increasingly withdrawn, Joei encouraged this attitude and took advantage of her sister's affection for her in order to gain power within the court.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. Because she was not chosen by Keiki, Joei is not the true ruler of Kei and unable to enter the royal palace at Gyouten and is forced to take up residence in the palace of the governor of Sei Province. Her claim to the throne is augmented by the machinations of the king of Kou, who arranges for his kirin, Kourin, to capture and enchant Keiki so that he is unable to speak and convince the people of Kei that Joei is the new ruler. Her possession of Keiki is enough to convince any remaining provincial governors doubting her legitimacy to support her, with the exception of Koukan, the governor of the Baku Province. Aided by the king of En, the true ruler of Kei, Youko Nakajima, is able to overthrow the false queen and Joei is ousted from Kei. (Source: wikia)
She is the daughter of Chou, previous Emperor of Kou. She and her brother elect to remove themselves from the Divine Registry after their father passes away and volunteered themselves into work brigades to help maintain the kingdom until the next king ascends. (Source: The Twelve Kingdoms Wikia)
Masashi Nakajima is the father of Youko Nakajima and husband to Ritsuko Nakajima. It is implied that he is a salaryman. Youko's father appears only in the Sea of Shadow arc and is unnamed in the novel. Little is known about him, and he is depicted as somewhat overbearingly strict and detached, expecting his wife and daughter to be supportive and submissive to his expectations. It is mentioned that Youko's high school was chosen by her father, who wanted her to attend a school close to her house and had neither a particularly bad or spectacular reputation, in spite of the recommendations of Youko's junior high school teachers for her to attend a more prestigious high school because of her high grades. Despite her personal preference for Youko to attend another school, Youko's mother agreed with her husband's decision. In another incident in Youko's childhood, she asked her mother for a pair of jeans to wear to camp so she could run in races against boys. Her father opposed the idea, saying that girls should not dress or talk like boys because it was shameful, and demanded that the jeans be returned. Youko's mother reluctantly complied, despite Youko's attempt to protest. After Youko is suddenly spirited away to the Twelve Kingdoms, her fate is unknown to the people back where she was born. Youko learns about how her parents have reacted to her disappearance through the visions brought on by the Suiguutou. While her mother is at a loss and hopes for her daughter's return, Youko's father accepts the idea that Youko has run away from from and has been concealing a delinquent lifestyle from her parents. When Youko's parents begin to argue, Ritsuko accuses her husband of not knowing their daughter at all and going to work without any concern for her disappearance, calling him selfish. In response, Youko's father suggests that if Youko had not run away, it is probably she was caught up in something and likely dead. (Source: 12kingdoms.wikia)
Kaka was the previous Royal Consort of Hou being the wife of Chuutatsu, and mother of Shoukei. Though Chuutatsu was reviled for his cruelty; Gekkei, the governor of Hou's Kei Province, understood that Chuutatsu's fall was because the king could not see that his harsh laws were hurting his people rather than helping them become upstanding citizens as he had hoped. However, Gekkei's understanding of Kaka is considerably harsher. He knew that while she appeared to be pious and humble before her husband in accordance to his expectations of the ideal citizen should act, she was an extremely extravagant and decadent woman. Though she was aware that her husband's laws were too harsh, she did not reprimand him but instead took advantage of his laws to further her own selfish whims. She ensured her daughter lived in complete comfort and would use her power to secretly eliminate anyone who she perceived as a rival for herself or her daughter. As result, she pressed false charges and ordered the execution of many innocent people. When the king is beheaded, Gekkei finds Kaka in seclusion with Shoukei and Hourin. He personally beheads Kaka for failing to take responsibility for allowing Chuutatsu to inflict great pain upon the citizens of Hou and for taking advantage of her power for her own selfish gain. (Source: The Twelve Kingdoms wikia)
Introduced as Shuurei's other servant at the palace. She was adopted by Taiho Sa after he saw her collapsed in front of his house due to the war eight years ago. She looks up to him a lot and was even willing to poison Shuurei and then sacrifice her life for him by drinking poison. After his death, she was sent to Taiho Sa's wife so she could live there. She traveled back to the capital with Ensei later in order to deliver information about the situation in Sa Province. (Source: Wikipedia)