A month after the defeat of Gorgom, Minami Kotaro is kidnapped by the Crisis Empire. After refusing to join them, he is thrown out into space where he undergoes the change to become Kamen Rider Black RX.
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.
In order to save the son of the Sahara Family from a wind-controlling knight, Kohtaro must travel to the Demon World where he discovers the truth about the realm of the Crisis Emperor.
Shigeru and Reiko become caught by Bosgun's moth monster, where Kohtaro has an hour to save them before they mutate into his minions.
Shigeru befriends a strange extraterrestrial sent by Gedorian to impregnate and ultimately overrun Earth in their numbers.
When a friend discovers plans for a massive Crisis poison gas weapon, Kohtaro must come to his aid and protect him while preventing the plans from falling into the wrong hands.
A girl who suddenly becomes a genius becomes the target for the Crisis Empire due to a secret kept from her by her parents regarding who she really is.
Maribaron decides to use one of Gedorian's weaker monsters to assist in a plot to brainwash humanity by manipulating the purity of a cactus-loving girl.
A monster replaces Shigeru with a perfect clone in a plot by Maribaron to replace all of Kohtaro's friends and allies in order to estrange him.
Gatezone employs an extremely powerful yet extremely rebellious member of his machine army to use his machine-controlling powers to defeat Kohtaro for the Crisis Empire.
A Crisis monster is brought in to manipulate Reiko's dreams to use her to draw suspicion against Kohtaro and thus use her against RX.
Shigeru finds a strange green stone needed by the Crisis Empire to activate their new dimension-switching device as the daughter of the scientist behind it pursues him to get it back.
When Maribaron accidentally kills the Crisis Emperor's cloned daughter, she decides to fix her mistake by abducting the Sahara daughter Hitomi as her replacement.
Pursuing Maribaron and Hitomi in the Demon World, Kohtaro is forced to fight against the assumed traitor Deathgaron, leading to a sorrowful encounter that awakens a new power in RX.
While still pursuing Hitomi, Kohtaro encounters a strange cyborg who wishes to work on his side, but is under the control of a harsh, mind-controlling warrior of the Crisis Empire.
With Hitomi fully transformed into Princess Garonia, Kohtaro has to figure out a way to finally resurrect her memories and save her before he, Shigeru and Joe the Haze are executed by Maribaron's pawn.
Kohtaro takes on Gedorian's Crisis monster mutating kids while giving them the delusion that they're flying squirrels.
Crisis creates a second sun over Tokyo, forcing the city to burn unless a scientist can develop a special magnetic gun that can eliminate the threat while under Kohtaro's protection.