Usagi is a sentient comb, a tsukumogami who gained consciousness after nearly a century of existence. She resides at the Izumo-ya lending shop in Edo-period Japan among other tsukumogami. Using her supernatural abilities, she assists the shop's owners, Okō and Seiji, in solving mysteries and addressing client problems. Her contributions bolster Izumo-ya's reputation for handling unusual cases involving tsukumogami or spiritual phenomena.