After defeating a group of robots in battle at an abandoned amusement park, a human resistance fighter slips inside Castle Promise, a massive robot-manufacturing facility. Luna Kozuki plans a revolt with the human workers; that night she sees Lucky and her old lover, Tetsuya Azuma. The next day, the rebels are betrayed by a fellow prisoner who was promised freedom; the collaborator is killed and Luna is captured. Akubon plans to publicly execute her as if she were Casshan, to break the people's spirit. However, the real Casshan saves Luna and kills Akubon, though the Black King escapes.