Gyokuyou is a silver fox deity, intrinsically connected to Kūgen Tenko yet initially hesitant to disclose the full nature of their bond. They possess silver-grey hair and distinctive yellow eyes, frequently appearing in shrine attire. Like Kūgen, Gyokuyou exhibits gender fluidity, capable of shifting between male and female forms, their true gender unknown or perhaps lost to time, shaping their identity as a non-binary spiritual entity.

Their personality merges dignified poise with shrewd pragmatism. Gyokuyou harbors a strong aversion to human-populated areas, a stark contrast to Kūgen's adaptability to modernity, stemming from a deep-seated disdain for humans influenced by past experiences involving Kūgen. Despite this, they engage in commerce with other supernatural entities, such as oni, trading magical artifacts for substantial compensation, transactions motivated by boredom and strategic interest rather than altruism.

Gyokuyou's dynamic with Kūgen is complex, characterized by unwavering respect and latent devotion. Though publicly dismissive of their connection, Gyokuyou's actions reveal a deferential, sometimes submissive, attitude towards Kūgen. This loyalty emerges during conflicts or collaborations, where Gyokuyou's abilities complement Kūgen's powers. Their elemental affinity aligns with metal, consistent with fox deity lore, and they wield significant spiritual capabilities, including shikigami manipulation for reconnaissance or combat.

Culturally, the name "Gyokuyou" translates to "Jade-Fuchs," reflecting their status among fox spirits. They operate within frameworks of tradition and duty, prioritizing roles that maintain supernatural balance over personal relationships. This is evident in their detached, transactional interactions with other entities, such as supplying artifacts to oni clans. Their narrative role often intersects with broader conflicts involving the Takagami family, though they avoid direct involvement unless necessitated by obligations to Kūgen or self-interest. Canonical developments beyond the anime's episodic arcs leave Gyokuyou's origins and specific history with Kūgen largely unexplored in official media.