Takeshi Hongo is a promising young man with a passion for motorcycle racing. However, his dreams are suddenly ruined when he gets kidnapped by Shocker, the evil secret organization planning to dominate the world. After being remodeled into a cyborg, Takeshi escapes and swears to protect the world from the inhuman monsters.

Kazuya Oki volunteers to undergo cybernetic surgery in the International Space Development Program in the United States to become an astronaut who can survive in outer space without the need for a bulky external suit. After a successful operation, he is given the codename "Super-1". Before he can depart for space, however, the base where he received his operation is attacked by the Dogma Kingdom. Only Kazuya can escape and is determined to avenge the deaths of the scientists, he returns to Japan and is trained by a martial arts expert, Master Genkai. With this knowledge, he can transform into the powerful Kamen Rider Super-1 to fight the evil Dogma Kingdom and later Jin Dogma.

A young journalist interviews an elderly woman about being forced into prostitution in Borneo at a brothel called Sandakan No. 8.