Akira Natsume, a high school student who hates machines, is hit by a truck in 2014 just as he resolves to change himself for the better. Sixteen years later, he wakes from a coma to find his brain housed inside EX-ARM No.00, a device described as a weapon of mass destruction. Police officer Minami Uezono and her android partner Alma have taken it from smugglers during an infiltration at Tokyo Harbor. When an enemy armed with EX-ARM No.08 attacks, they activate No.00 as a last resort. Aboard the smugglers' ship, Akira overcomes his reluctance, fights through Alma's body using martial arts, and hacks the vessel itself. Back on land, he meets the police team formed to counter EX-ARMs and decides to join them in stopping the harm these weapons cause. The series is a sci-fi action story.