Shin Kamen Rider: Prologue (真・仮面ライダー 序章(プロローグ),Shin Kamen Raidā: Purorōgu?, translated as True Masked Rider Prologue) is a 1992 V-Cinema film in the Kamen Rider Series. Shin is the eleventh production in the franchise, at the time heavily straying from the roots of the franchise. As a work celebrating the 20th anniversary of the franchise, the film targeted the now-adult fans of the original, taking the bare essence of the Rider character and his origin, placing it in a violent, realistic and modern setting and conveying the driving sorrow of the Kamen Rider character, who finds himself in the center of conspiracy and turned into a superhuman being against his will. Such a drastic change in the franchise put off some viewers and the film wasn't seen as much of a success, therefore eliminating chances of the planned follow-up. On the other hand, some were simply put off by the violence in the film, seeming to be heavily inspired by David Cronenberg's The Fly. This movie features a Kamen Rider whose characterization is closer to a Tokusatsu monster than a hero.
Shin was released on DVD on April 25, 2008, by Bandai Visual. Toei's subscription channel featured Shin during its special Kamen Rider 40th anniversary line up in July 2011.
Doctors Kazamatsuri and Onizuka are geneticists researching cures on diseases such as AIDS and cancer by performing experiments to strengthen the human body. The test subject is Shin Kazamatsuri, the motorcycle racer son of Doctor Kazamatsuri. Unknown to them, their operation is funded by a syndicate group, who plan to use this research to have the bodies of men strengthened for their own gain—they have already been experimenting in the field of cyborg soldiers, to a less-than-successful attempt. However, they did not count on Onizuka's own secret ambitions; the mad Onizuka wanted to create a new species, by fusing a grasshopper's DNA with the test subject's, in order to start a new civilization and be their god. He has tested on himself, but seems to be having greater success with Shin.
Meanwhile, a murderous creature is stalking the city, while Shin dreams of it. While he believes he is the one causing the murders, he eventually finds out Onizuka's plan and discovers that it's Onizuka who has been behind the killings. Onizuka has experimented on himself and altered his genes, making him a humanoid grasshopper; the telepathy of grasshoppers allowed him to communicate with Shin, resulting in his witnessing the murders.
The syndicate learns of Onizuka's plans and have him institutionalized. As if the syndicate were not enough, a CIA agent tracks Shin and wants him eliminated, for he doesn't know the true threat he could pose. The repulsed Shin digs to find out all he can about the experiment he foolishly volunteered to be a part of, which is now altering his body and putting him and his loved ones in danger.
Before the name "Kamen Rider Shin" was decided, Shotaro Ishinomori originally planned for the character to be called "Kamen Rider Gaia" (仮面ライダーガイア,Kamen Raidā Gaia?). The design of this Kamen Rider Gaia was originally more of a traditional Kamen Rider appearance, before later designs switched to a "Kamen Rider Style Reform" version (resembling a man in a motorcycle helmet and modified riding jacket), and then the mutated insect-like human that would become Kamen Rider Shin.
Shotaro Ishinomori, the creator of Kamen Rider, appears early on in this film as a spy investigating the research of the company.
This is the only film entry in the franchise to feature scenes of nudity.
Despite being labeled as a 20th anniversary event, the franchise was actually in its 21st year in 1992. The real 20th anniversary was on April 3, 1991.
