Was aired from 1988 to 1989 and ran for 47 episodes. Half a year after defeat of Gorgom, Kotaro is later captured by the Crisis Empire and offered a place in their group. When Kotaro refused, his King Stone was shattered and he was thrown into space where the sun's radiation mutated his King Stone and he mutated into Kamen Rider Black RX. With his new powers, he battles the Crisis Empire. This is the final show in the Shōwa era of shows.