Ken Kanzaki, a skilled investigator in a technologically advanced metropolis known as "Tokyo City," is entrusted with protecting a prominent event hosted by the powerful "Zaizen Konzern." When robotic apparitions unexpectedly attack during the party, Ziazen is killed and Ken along with fellow investigators Jun, Ryo Aguri, and Go Goda are severely injured. However, they are saved by Metropolitan Police scientists who transform them into cyborgs. Days later, a robot force commanded by the mysterious "Ido" invades a floating-town in Tokyo Bay, leaving the police and military helpless. But three young men, now dubbed the "Armored Police Metal Jacks," equipped with mechanized suits, come out to save the day. Wearing their "Jack Suits" and "Jack Armors," they quickly annihilate the robotic corp and succeed in their mission. This marks the start of a new battle between the "Metal Jacks" and high-tech criminals, with the futuristic backdrop of Tokyo City providing the setting for their clashes.