TV-Series
Description
Gyokumen Koushu, also known as Princess Gyokumen, is one of the primary antagonists in the narrative. She is a youkai who proclaims herself the mistress of the powerful demon king Gyumaoh, and her singular, all-consuming goal is to revive him so she can take him as her lawful husband.

Underneath a carefully maintained elegant appearance, Gyokumen possesses a personality that is highly manipulative, cold, and cunning. She is driven entirely by her own self-centered desires, viewing nearly everyone around her as nothing more than tools to be used and discarded for the sake of her ambition. Her obsession with reviving her lover leaves little room for any other sentiment, including affection for her own daughter, Lirin. Gyokumen shows her no motherly love, treating the girl solely as a servant or a means to an end whenever it suits her needs. She is also portrayed as a jealous and possessive individual, which is reflected in her desire to marry Gyumaoh while leaving his lawful wife, Rasetsunyo, in a sealed and petrified state.

Gyokumen is the instigator behind the central conflict, as she is believed to be responsible for breaking a five-hundred-year-old seal and releasing the Minus Wave upon the land of Shangri-La. This forbidden mixture of youkai magic and human science, developed with the help of her ally, the twisted bioengineer Dr. Ni Jianyi, is what drives the demon population mad and shatters the peace between humans and youkai. Her ultimate plan requires the Heaven and Earth Scripture, a set of five sutras, to fully revive Gyumaoh, whose body is kept in a special incubation chamber. To that end, she manipulates Gyumaoh's son, Kougaiji, by promising him the revival of his mother, Rasetsunyo, in exchange for retrieving the sutras from Genjo Sanzo. She proves to be a ruthless schemer, even allowing Dr. Ni to perform brainwashing experiments on her own subordinates, including Kougaiji and her daughter Lirin, to further her goals.

Gyokumen has a significant working relationship with Dr. Ni Jianyi, a sadistic and mysterious scientist who endlessly researches the fusion of science and magic for the purpose of reviving Gyumaoh. In the original source material, there are implications of a more intimate relationship between them as well. According to creator commentary, her role as the top antagonist was a deliberate choice. She is positioned as a dark parallel to the merciful deity Kannon, serving as a mother-type figure on the enemy side, but one defined by selfish desire rather than compassion. As a youkai, Gyokumen does not demonstrate unique combat abilities in the same manner as the main characters, but her power lies in her resources, her authority to command powerful demons, and her use of Dr. Ni's inventions to track and attack the Sanzo party. Her name translates to "jade-faced" or "jewel-faced princess." Her appearance in the series features her with long lavender hair tied up, violet eyes, a beauty mark below her right eye, and a revealing violet robe, presenting an image of exotic beauty that belies her cruel nature.