Issei Hyoudou, also known as by dossier code BK201, is the protagonist of the story, "Darker Than Black." He is a second-year student at Kuoh Academy, and a member of the school's infamous "Perverted Trio," a group of perverted boys in the school. He is also member of the organization, "Gate Royale," a group composed of Contractors and humans. He is also the leader of Team Black Moonlight, partnered with Matsuda, Motohama, and Mao, three fellow Contractors, and a Doll by the name of Yin.