Azumi Azuma is head priestess and owner of Tenkai Shrine, an ancient temple near Kamaya City's ocean side offering tourist hot springs and overnight stays. She shares a long-standing friendship with the Kusanagi family and possesses full awareness of Yuma Kusanagi and Matoi Sumeragi's exorcist activities. Despite her advanced age, she exhibits a vibrant, playful personality, enthusiastically adopting modern teenage trends and openly admiring attractive men. She demands the affectionate nickname "Azu-chin," reflecting her preference for casual, youthful interactions.

Her light grey or pink hair typically features buns and ribbons, often portrayed with closed eyes. While traditional kimonos obscure her figure, Exorcist Regalia and casual outfits reveal a fuller bustline that others note favorably. She harbors distinct romantic feelings for Cariot of the Vatican's Anti-Creed service, displaying overt jealousy toward women who engage with him—particularly Haruka Luciela.

Though frequently lighthearted and childlike, she shifts to situational seriousness when supporting Matoi and fellow exorcists. Her prior active exorcism damaged her higher-dimensional being, restricting current combat effectiveness, yet she offers guidance and aid to younger exorcists as circumstances require. Rumors indicate she witnessed the initial encounter between Matoi's parents, Shingo and Shiori Sumeragi, near Tenkai Shrine.