Ryōko Yakushiji, a Superintendent in the Tokyo Metropolitan Police Department and a graduate of Tokyo University's Law Faculty and a multilingual person, works with Junichirō Izumida to investigate seemingly paranormal, supernatural or bizarre events that get involved in criminal cases. Ryōko works with her colleagues and subordinates, including her rival Yukiko Muromachi, alongside JACES security forces personnel and her personal maids Lucienne and Marianne to resolve the cases before they go out of hand.