Celine Argente, an internationally wanted perfumer adept in the art of poisoning, has entered Japan with a group of conspirators, and among them is a former member of the Metropolitan Police Department. The aims of these six criminals—as well as their employer’s identity—are shrouded in mystery, but with a little help from the FBI, Kuroko just might be able to track them down! As her investigation begins, an invisible poison creeps through the streets of Ruruie...