Kamyu is a princess of Onkamiyamukai, a theocracy of peace-keepers ruled by the angel-like Onkamiyaryu, and the younger sister of Urutorii. Her most distinctive physical trait is her black wings, which are highly unusual for her race, as members of her kind are typically born with white wings. She has silver hair that falls just below her ears, rich deep blue eyes, and wears a brown dress with dark blue puffy sleeves, white cuffs, and red trimming, complemented by a light blue belt and brown boots. She is generally perceived as a hyperactive teenager due to her energetic and outgoing nature, though she is equally content to engage in quieter activities as long as she is in the company of her friends. While playful and sweet, her past is a sensitive subject; before coming to Tuskur, she was ostracized by her own people who either treated her like a monster because of her black wings or were overly respectful due to her royal status, which prevented her from forming any genuine friendships.

Kamyu's role in the story begins when the delegation from Onkamiyamukai arrives to establish ties with the nation of Tuskur. During this time, she initially frightens a young girl named Aruruu, but on the advice of Hakuoro, she uses a honeycomb to make peace, which successfully leads to a close and lasting friendship with Aruruu and another girl named Yuzuha. These three, along with the giant tiger Mukkuru, are often seen playing together, representing Kamyu's first experience with true companionship. Beyond her role as a playful adolescent, she shares a deep bond with her older sister Urutorii, who sometimes scolds her mischievous behavior but is dearly loved by Kamyu. She also acts as a caretaker and older sister figure to Kuon, who describes Kamyu and Aruruu as the two most overprotective members of her family.

Throughout the narrative, Kamyu demonstrates notable development, particularly in her later appearances during the conflict between Yamato and Tuskur, where she takes an active role in logistical strategy by distracting and redirecting enemy supply lines. She is also involved in a significant supernatural plot point, as she is the incarnation of a being named Mutsumi, whose spirit resides within her and sometimes causes her to show signs of fear about this fate. In a climactic moment after Kuon is freed, Kamyu works in unison with Mutsumi and her sister Urutorii to permanently seal away a dangerous god, speaking with a dual voice to apologize to her father for the necessity of the act. In terms of abilities, as a member of her winged race, she possesses inherent thaumaturgical powers, with her specific skills relating to fire and darkness magic.