With World War II looming, intelligence regarding the social and economic conditions of other nations has become a valuable asset. Consequently, Japan has established a new spy organization called the "D Agency" to acquire this advantage. Under Lieutenant Colonel Yuuki's command, eight agents have been tasked with infiltrating and observing some of the most powerful countries, reporting on any developments linked to the war. To perform these dangerous duties, these men have conditioned their bodies to endure extreme conditions and studied various fields, including communications and languages. However, their greatest strength lies in their ability to manipulate people to secure the information needed to give their nation the upper hand.