The art masterpiece, "Mona Lisa," is once again exhibited in Japan. To enhance theft prevention, the museum recommends Riko Rinda, the all-around appraiser with astonishing insight and memory, to undergo authenticity appraisal training at the Louvre. Riko travels to Paris with reporter Ogasawara, but as she delves deeper into the research of "Mona Lisa," she gradually loses her appraisal abilities! A conspiracy unfolds around the 500-year-old mystery within the painting. Can Riko escape the strange influence and uncover this enigma?