Takeshi Hongo, a young scientist boasting of an IQ of 600 and a racing prodigy, is abducted and his body surgically remodeled by Shocker, an evil secret society plotting for global domination. Hongo wins the championship, but the model who brings him his bouquet suddenly bares her fangs and attacks! With growing suspicion, Hongo investigates the woman's home, and finds it has been transformed into a lab. Shocker tests their mysterious Scorpion Man by releasing their slave workers and telling them that they can have their freedom if they can escape within 10 minutes, but one by one they die at the Scorpian Man's hands. At an amusement park's botanical gardens, people begin to go missing. The young boy Kenji's older sister Yukie gets snatched away, and he tries to tell someone that his sister was attacked by a giant King Sarracenian!! While a series of strange earthquakes are going on, Hongo is contacted by his childhood friend and seismologist, Amemiya Chikako, who tells him, “Something is planning to cause a major earthquake.”. Former navy lieutenant-commander Sunada is attacked by the Chameleon Man. His aim is a submarine model in Sunada's possession that has secrets relating to a Nazi treasure concealed inside. Kamen Rider: S1 E7 - Duel With Grim Reaper Chameleon! World Fair Impression. Masked Rider, having fallen into a pit trap, loses his power in the secret room where no wind can reach and reverts back to his form as Hongo.EPISÓDIOS
- Hongo begins an investigation into the series of incidents where people who had glasses made at Kagemura's Optometry store have gone missing.
- But even Ruriko gets some lure glasses, and she disappears as well.
- Cobra Man makes an attack on the gold vault, but when the pet dog of security guard Kondo barks at him, he drops his fangs!
- Seeking his fangs, he attacks Kondo.
- Ritsuko Ayakoji of the Ayakoji Biology Research Institute, Shocker's collaborator, puts up advertisements for “Purchasing Animals” to gather animal blood and capture the people who bring in their pets.
- Kamen Rider: S1 E11 - Bloodsucking Monster, Gebacondor.
- Shocker has produced a new monster, Gebacondor, by assembling into one all the strong points of their previous monsters.
- But Gebacondor needs the lifeblood of young women.
- Doctor Shirakawa has invented a death ray but tries to seal his invention away, while his aid Shibata conspires with Shocker and is remodeled into the monster Geckogeras, making secret plans to take the death ray.
- Kamen Rider: S1 E13 - Tokageron And The Big Monster Army.
- To break through the Toyo Atomic Energy Research Laboratory's barrier, Shocker remodels pro soccer athlete Nomoto and produces the monster Tokageron with powerful kicking might.
- Kamen Rider: S1 E14 - Raid Of The Demon Sabotegron.
- Taki receives word that a new Shocker leader is coming to Japan from Mexico and meets up with the one who contacted him, but they transform into Sabotegron.
- Kamen Rider: S1 E15 - Counterattack, Sabotegron.
- At the end of fierce fighting, Masked Rider drives Sabotegron away.
- Sabotegron then uses Flowers of Mexico to attack Hayato and the Tachibana Racing Club.
- Kamen Rider: S1 E16 - Wrestler Of The Devil, Pirasaurus.
- Shocker gets their hands on the Pirazaurus whose poison can kill a giant dinosaur in mere seconds and begin to create a cyborg by combining it with a human.