Chui-Bi was the concubine of the previous king of Myung-Joo and the biological mother of Mu-Hyang.
Green hair tied in a bun in the back with a pin through it.
Chui-Bi was the daughter of the Second State Councillor in the court of Myung-Joo. Apparently favoured due to her status to become queen, Chui-Bi resented how the King of Myung-Joo never truly expressed any interest in her. However, she continued to maintain the belief that the King would eventually marry her due to pressure from his advisors and the lack of other suitable candidates. At some point, Chui-Bi gave birth to Mu-Hyang. Though everyone believed that Mu-Hyang was the son of the king, he was actually the son of an unknown man.
Chui-Bi was devastated when the king married Ga-Bi, an unknown woman who offered no political advantage to the king and eventually gave birth to a son, Hong-Ryung, who would be the king's official heir. However, the king never claimed that Mu-Hyang was not his son, leading Chui-Bi exercised the belief in court that Mu-Hyang could become the king's heir if Hong-Ryung did not prove to be suitable.
Upon the king's death and Ga-Bi's disappearance, Chui-Bi attempted to undermine Hong-Ryung's status as the King of Myung-Joo, emphasizing that it was the king's weakness that resulted in Myung-Joo never gaining a divine bell of its own, and a series of assassination attempts. Despite being an obvious threat in court, she is unaware that she is only allowed to remain out of the king's own compassion towards Mu-Hyang and that both her son and the king have been aware for a long time that Mu-Hyang is not the king's son.