Heartbroken and new to Kyoto, seventeen-year-old Aoi Mashiro wanders into a charming antique shop in the hopes of selling her grandfather’s art scrolls and using the money to visit her ex-boyfriend in Omiya, just north of Tokyo. However, the antique shop owner’s enigmatic grandson, Kiyotaka Yagashira, sees right through her façade but notices she has a discerning eye when it comes to spotting forgeries and offers her a job at the shop. Kiyotaka himself has been a talented appraiser since childhood and has a habit of astutely evaluating both the antiques and their owners alike. This gift has earned him the nickname “Holmes” among his family, co-workers and classmates, as well as all sorts of people that he and Aoi meet across the city.

As part of her role at the shop, Aoi joins Holmes on a series of five different cases, each more mysterious than the last. A manga artist struggles to understand the deeper meaning hidden in a matcha tea bowl from his recently deceased father; a university student is appointed as this year’s Saiō-Dai (the highest honour a woman can receive in Kyoto) but begins to receive cruel, anonymous letters in the process; and a fight breaks out when a local antique dealer claims one of the Bizen wares that he’s selling is a rare, salvaged item. Things escalate in the fourth case when three brothers are each bequeathed very different works of art by their deceased father who was a famous author; then the final story sees Holmes and Aoi each confront important people from their pasts. The novel ends with the two of them attending Kyoto’s famous Gion Festival together, their romance simmering beneath the surface, and with many more mystery cases ahead of them.