In a street that was to be named "Unit Blue" in the near future, there is a town named "Night Town". A town engulfed in darkness of the night due to a lack of electricity. A young man there, Sanada Hajiki works part time in a transport business known as Hachisuka Transporation.
One day, Hajiki gets in touch with a client who wanted him to transport a mysterious material known as "GAD" for a high price. When the "GAD" ends up as scrap, it takes the form of a giant humanoid machine known as iron man "Lightning".
From then on, all kinds of people who also owned an iron man appeared before Hajiki. Kanata - an outlaw who used iron man "Zero" to destroy, Aiko - an upperclass young lady who searches for friends with iron man "Messerschmitt", and Takumi - a young man who works for justice with his iron man "Thunder Bolt".
Even though Hajiki is also a iron man user himself now, his thoughts differ... Those who are always seeking for danger, those who want to meet friends and those who fight for justice. As Hajiki is troubled over such differences, he must fight alongside his own iron man against other similar humanoid mechas.
Why did "GAD" and iron men appear before them? The gears of fate for the young men who posess iron men have begun to work...
Note: The real episode 6 ("The Five Masks") wasn`t aired in the first run. The correct order was restored in all subsequent airings on other channels and on the DVD release.
