Akira Natsume lives a relatively ordinary life, save for his crippling fear of electronic devices. In contrast to Akira, his brother Shuuichi excels in virtually every aspect of life and Akira is determined to follow in his footsteps. However, Akira's plans are put on hold when he is hit by a truck while trying to rescue a girl from delinquents.
When he awakens, Akira discovers that he has been transformed and is now embedded within a highly advanced weapon known as an EX-ARM. Moreover, 16 years have passed since his devastating accident. Minami Uezono, an officer of the law, reveals to Akira that by way of the EX-ARM, he possesses the power to cause immense destruction. Accompanied by an android named Alma, Minami is on a mission to retrieve Akira's EX-ARM from an enemy smuggler ship.
Although Akira is initially confused, he quickly learns to harness the capabilities of the EX-ARM. Eventually, he meets the head of the EX-ARM Countermeasure Division, a police department that aims to prevent crime caused by machines. Akira takes on the responsibility of fighting these despicable crimes and uncovers some truths about his unique condition along the way.
