Tomoe, a god presiding over the Mountain Pass Resort near Sakurashinmachi, ascended to godhood from her origins as a dog. This transformation fulfilled promises to others, granting her continued existence and future enjoyment of life alongside them. Her ascension followed witnessing Oushyuu Hiizumi tune the Hiizumi branch family and himself.

She possesses light skin, red eyes with thick lashes, and light blonde hair featuring a prominent central forehead curl. Canine ears top her head, complemented by a large, matching blonde tail. Tomoe typically wears a gilt kimono secured by a black obi decorated with a black leaf motif. She manifests in both adult and child forms; her adult stature exceeds Kyōsuke Kishi's height, while her child form matches Yae Shinatsuhiko's child form height.

Her personality reflects patience, resilience, fortitude, and loyalty, embodying values akin to the Bushido code. Tomoe's canine roots deeply influence her loyalty, while her divine, anthropomorphic nature fosters discretion and a preference for seeming ordinary to new guests. Generally composed, she reveals a competitive streak in sports like table tennis or sword fighting against worthy opponents. Kind to humans, she dedicates herself to serving them through her resort. However, she holds distinct views on divine intervention in human affairs, leading to disagreements with figures like Yuhi. Comfortable with her sensuality, she can be flirtatious while clearly asserting personal boundaries.

Historically, Tomoe reduced troublesome yōkai activity around Mount Hakone. She formed a friendship with Yae Shinatsuhiko, and her interactions with Kyōsuke Kishi are noted.