Kaki is the name given to the Taisai of Kei when Youko ascends the throne in the anime. He is unnamed in the Japanese version and is referred to by his rank. It is believed that the Taisai was a graduate from the Shoujyuku. He is depicted as a man who is willingly to listen to Youko's requests to improve the kingdom, in contrast to most of the other ministers who seem dismissive of Youko's inexperience and lack of general knowledge.
The Taisai serves as the Palace Administrator and Minister of Court, who is unnamed in the novels. As the most vocal opponent of Seikyou, the chousai, Kaki conspires with the Sankou and Koukan in order to free Youko from Seikyou and his faction's influence at court, resorting to measures like abducting her if necessary. It is implied that the Daishikuu of Kei is also aligned with the Taisai's faction.
When the plan fails and Uikyou, the Taishi, is murdered, Kaki is arrested. He is later found dead in his cell by the Minister of Law when Youko requests to interrogate him. Though it is suggested by her ministers that Kaki committed suicide to avoid responsibility, Youko and Keiki suspect foul play was involved with his death.