During a motocross practice, Keisuke Jin is ambushed by two Myth Cyborgs created by a secret organization that's attempting to control Japan, G.O.D. (Government of Darkness). He transforms into Kamen Rider X, but little does he know that his battle is recorded and analyzed by King Dark, G.O.D.'s commander, to create a super cyborg. Other G.O.D. cyborgs are attacking all over Tokyo and in the middle of the crisis, the original four Riders return to Japan from different countries around the world. The five Riders unite to lead a counter attack against G.O.D.
Unfortunately the movie Five Riders vs. King Dark is not yet available on HBO Max.
| Crew | Shotaro Ishinomori | Creator |
| Production | Tôru Hirayama | Producer |
| Production | Seiji Abe | Producer |
| Sound | Shunsuke Kikuchi | Music |
| Camera | Ryuji Kawasaki | Director of Photography |
| Editing | Junkichi Sugano | Editor |
| Writing | Masaru Igami | Writer |
| Directing | Itaru Orita | Director |
