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.

Kotaro looks for his step-brother Nobuhiko Akizuki and plans to track down Golgom's headquarters.

Kotaro investigates a bizarre string of abductions in conjunction with a scheme by Bishium to bring him down.

A cycling friend of Kotaro becomes the subject of Golgom's mad doctor experimenting to find a weakness to their escaped subject.

Kotaro discovers the whereabouts of a missing biker, who is raising his son to ride and protect the ultimate bike devised by his father.