Since the collapse of the DARK organization, Jiro has been wandering about, wondering whether he will ever see Mitsuko again. On his journey, Jiro encounters a beautiful girl named Rieko, who is protecting Akira, a young boy, from the evil Professor Gill. Ironically, Akira is Professor Gill's son, but he is also the key to Gill’s menacing secret weapon and his plans to conquer the world.