The time is the end of the Meiji period. Kai Ichijoji is a young man who studied Western medicine in Nagasaki and lives in a tenement house in downtown Tokyo. In fact, he is also the son of the Superintendent General, who makes various inventions based on the rare things he saw and heard in Nagasaki. The crimes and incidents that occur one after another in the rapidly developing imperial capital, Tokyo, are vividly uncovered by scientific investigation and inspiration...!