Yomi Kasuga (春日夜未, Kasuga Yomi) is a demon tamer, and her partner is an ogre Ayakashi named Yoki. She is introduced as an investigator from The Shadow Organization and an ally to Tokine and Yoshimori, but later betrays them and reveals her true intention of using Karasumori's power to make Yoki much stronger. As a child, Yomi worked with Tokine's father Tokio Yukimura, but inwardly resented him because he reminded Yomi of her own weakness.