Hanamori Ichiko uses her leave to come to Paris. She encounters the members of the Thirteenth Section who are enjoying sightseeing in Paris after cooperating in an investigation with Interpol. Ichiko is thrilled by the romantic atmosphere of Paris which has been decorated for the Christmas season. At that moment, a phone call on the occurrence of a case comes in from Section Chief Monma who is in Tokyo. The Thirteenth Section ends up having to return to Japan. However, Shigemura Kanichi is missing. It seems that he got separated from them. Ichiko immediately uses her nose to try to locate Shigemura, but she gets lost in the process of doing so and wanders around unfamiliar streets. It is strangely the regular landscape but something about it is odd. A private detective with a topknot charges past her. And on the riverside, a board with an edict on “mercy for living things” has been erected. “Eh? This is the Edo era?” a bewildered Ichiko wonders. Could she have gone back in time? ~~ Adapted from the manga "Deka Wanko" by Kozueko Morimoto.