What is justice? What is evil? The undercover investigation team, commonly known as "Group D" confronts the darkness of organized crime. Kurosawa Hyogo, once a habitual criminal dealing in theft and violence, is recognized for his high IQ, judgment, and physical ability. He is added to the secretly formed undercover investigation team. Its mission is to infiltrate various criminal organizations, including gangs and fraud groups, to obtain information and evidence about crimes. The group includes Date Naoya, the dark doctor Minamoto Reiko, and the white hat hacker Miyanaga Soichi. Recently, a fraud case has occurred in the jurisdiction of the Hyogo prefectural police. Group D is tasked with infiltrating a gold company that that is apparently involved.