As the demon army threatens the human realm, Knight Luvilia bravely challenges the Demon King Vois. With the aid of the Demon God Tia, Vois emerges victorious, binding Luvilia to his will. Overwhelmed yet determined, she manages to teleport away after the confrontation. Vois then bolsters his forces by adding his younger succubus sister Ilis and the talented witch Lufilia to his team for the battles ahead.