Sumire was a student at the Tsuzura Temple and classmate of Kanaka Kagami. When Kanaka was bullied, Sumire tried to apologize to Kanaka for not helping which Kanaka did not care. Sumire is chosen to take the exorcist exam along with Kanaka and her bullies, Hiyori Higashina, Kusumi Kuzusumi and Aruko Abataya. During their final exam a Kazenbou, a powerful Amasogi which had killed Kanaka's family attacked them. The group's effort failed to damage the monster, but Kanaka was able kill it with ease and began to show her first signs of emotion. Sumire and Hiyori were often targets of Kanaka's "skinship".