Half a year after the downfall of Gorgom, Kotaro Minami has gotten a job of a helicopter pilot in a business owned by the Sahara family. 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 and thwarts their plans to take over Earth. (Wikipedia)