Anju Ryou is the former Deputy Secretary of the Department of Royal Commandment Affairs. Anju is a very charming man in his late 30s who possesses a strong resemblance to Sakujun Sa; Shuurei notes being around Anju reminds her of Sakujun. Anju frequently teases others, particularly Kouki Ki, and flirts with women, especially Kochou whom he raised. When Shuurei asks if he comes from a noble background, Anju casually mentions that he was adopted into a noble family.
Despite his appearance, he is a dangerous and astute individual; it said that one risks their own life by being near him and he has killed many people in his life. Due to his mysterious powers, it is suggested that he may be the vessel of the Black Immortal. Anju is later revealed to be Sakujun's older half-brother, as well as the secondary antagonist of the series. Using Shuurei's life force, Anju revives Sakujun as an undead puppet. The puppet is manipulated into destroying sacred artifacts and attempting to assassinate members of Hyou Clan. Though he fails to kill Lady Eiki and Shusui, he succeeds at eliminating Ruka Hyou and locating where Shuurei's slumbering body has been kept in the Hyou clan's crypts. By having Sakujun abduct Shuurei, Anju attempts to use her against Ryuuki. He disappears after Ki Ou's death.