|Romaji Translation||Ou Hien|
|Debut (Light Novel)||Volume 17|
|Appears in||Light novels|
|Family|| Ou Ki (Father) |
Hyou Riou Sr. (husband)
Hyou Ruka (Sister-in-law)
Hyou Riou Jr. (Son)
Ou Tsuyuri (Aunt)
Her personality was similar to her son Riou, as she was also very determined to fulfill whatever she wished to do.
Revealed to be a direct descendant of the first emperor of Saiunkoku, her actual name is "Sou Hien." During the time when Ou Ki was the chief of the Censorate, he had been charged with the dealing of the locust plague. In order to gather information from the Hyou clan regarding this, he had sent his daughter Hien to the Hyou clan to marry her off so that she could easily send him information. Hyou Ruka was aware of this, but still allowed her to marry her brother in order to preserve the blood of the Sou family. She determinedly confronted Riou and convinced him to marry her. After that, Hien sent many detailed reports to Ou Ki.
Hien was later on the verge of death due to childbirth and Ruka put her in a stasis so that she could fix her someday. While she was in slumber, her body was used as Ruka's vessel. Ruka later switched into another body while leaving Hien asleep. After Kou Shuurei was put to sleep in the Hyou Clan's crypt, Hien woke up and decided to use her remaining time to guard Shuurei. She later helped to absorb back Shuurei's lost life force.
She married him only for the sake of getting into the Hyou clan. Riou also never looked at her as he was always obsessed with the Rose Princess. In fact, Riou only sired a child with her because Ruka had asked him to.
Hien deeply loved her father as she was willing to use herself to serve his purpose. She went as far as to marry into the Hyou Clan to help her father.
Hien's relationship with him is unknown but she must have been close with him. It was implied by Tei Yuushun that Kouki was in love with her.
Hien first meets her son during the last battle of the final volume. Her last words are for him as she says that she's sorry she was never by his side, giving him love and care.