Ginji is a central figure in the narrative surrounding the inn Tenjin-ya, recognized as a nine-tailed fox ayakashi and the young master of the establishment. His history with Tenjin-ya is relatively recent, having been employed there for less than fifty years, as he originally worked for Orio-ya, a major rival inn. This prior association is a source of some personal insecurity, as he confesses to feeling a lingering wariness from other staff members who may not entirely trust him due to his past. Despite being the young master, he runs a small, struggling restaurant in the inn's garden annex that sees few customers, a situation that changes dramatically with the arrival of the human protagonist, Aoi.

In terms of personality, Ginji is typically seen as kind, caring, and remarkably helpful, especially toward Aoi. He was one of the first residents of the Hidden Realm to treat her with genuine kindness, and he quickly becomes her most steadfast supporter and collaborator. His enthusiasm for her human-style cooking is immense; after tasting her food, he immediately believes it could be a huge success and proposes that she take over his restaurant as a way to settle her debts. He frequently brainstorms menu ideas with her and assists in procuring rare ingredients, leading them to name their establishment Moonflower. While his demeanor is generally cheerful, laidback, and amicable, he possesses a far more intense and serious side that emerges whenever Aoi is in danger or treated disrespectfully, making him a quick and loyal defender. Late into the story, it is revealed that Ginji was the ayakashi who visited a young, starving Aoi in the human world, leaving her food to save her life, a secret that deepens their connection.

Ginji's motivations are deeply tied to his relationships and past. He shows considerable respect and loyalty to Odanna, the ogre who runs Tenjin-ya, and is close enough to use his child transformation to trick him into buying treats. However, his most complex relationship is with Ranmaru, the owner of Orio-ya. They share a long history, having been raised together by Princess Iso, a former Hachiyo who was a mother figure to them both. Three hundred years before the main story, a crucial ceremony failed, forcing Princess Iso to sacrifice her life. Ginji carries immense guilt over her death, believing his own impulsive actions led to the catastrophe. Following this tragedy, he grew apart from Ranmaru, disapproving of the increasingly strict and demanding way he ran the inn, which ultimately led Ginji to leave for Tenjin-ya. Despite this rift, he continues to honor a deal to temporarily return to Orio-ya every century to help Ranmaru prepare for the vital ceremony that ensures the wellbeing of the Southern Lands, and through Aoi's influence, they begin a gradual reconciliation.

Ginji possesses the notable abilities intrinsic to a nine-tailed fox, primarily the power of shapeshifting. He can transform into nine distinct forms, including his standard handsome young man with white hair, blue eyes, and fox ears; a young boy with proportionally large tails; a beautiful woman; a tiny, fluffy fox; and a full-grown kitsune. He maintains his signature nine white tails in almost all of his forms, and he uses these transformations for various purposes, such as appearing less threatening when introducing himself to Aoi or performing in important ceremonies.