Kotaro Minami, a youth on the run from the mysterious organization known as Golgom, begins to awaken into a horrifying new form granted to them due to their greater plans for him; making him choose to use it instead to fight them as Kamen Rider Black.

Some time after the defeat of Gorgom, Kohtaro Minami attempts to create a new life for himself in peace. But when the Crisis Empire arrives to conquer Earth, they come prepared to deal with the hero; forcing him to awaken a new power to face this new threat.

Kohtaro begins to realize the new power he has gained by becoming Kamen Rider Black RX, even as a robotic member of the Crisis Empire has him targeted for battle.