Following the downfall of the DARK group, Jiro roams aimlessly, pondering the chance of reuniting with Mitsuko. Along his travels, he encounters Rieko, a captivating girl safeguarding Akira, a young boy targeted by the malevolent Professor Gill. Unbeknownst to many, Akira is not only Professor Gill's offspring but also the linchpin to his dangerous weapon and world domination schemes.