Nonko Arahabaki is a resident of the Yuragi Inn and a former member of the Yoinozaka family, one of the three great spiritual families in Japan. Born under the name Nonko Yoinozaka, she is a female oni and a descendant of the legendary oni Shuten-doji. She left her family and clan to pursue her own path, becoming a professional manga artist. In her daily life at the inn, she is known as a friendly, easygoing, and carefree person, often seen enjoying alcohol or working on her manga. Despite her relaxed demeanor, she becomes serious and dedicated when facing a deadline, and she shows a focused, determined side during battle as well.

Her motivations center on living independently and following her passion for creating manga, free from the expectations of her prestigious lineage. She enjoys the camaraderie of the inn's other residents and participates in both everyday activities and supernatural conflicts. Nonko’s oni abilities grant her superhuman strength and durability, and her combat power is closely tied to alcohol consumption. Drinking enhances her fighting capabilities, but if she has not consumed any alcohol or drinks too much and becomes fatigued from a difficult battle, her performance suffers. This up-and-down relationship with alcohol is a distinctive trait that affects both her battles and her daily interactions.

In the story, Nonko acts as a supporting character who brings humor and warmth to the group. She maintains friendly bonds with the other tenants, particularly with Kogarashi Fuyuzora, Yuuna Yunohana, Sagiri Ameno, and Chitose Nakai. While she does not undergo a major romantic arc, her personal development is shown through her choice to leave her family name behind and build a life as a mangaka, demonstrating her independence and resolve. Her notable abilities include her oni strength, enhanced by alcohol, and her serious approach to combat when necessary, making her a capable ally in the face of supernatural threats.