Kamen Rider: The First

One year prior, two terminally ill hospital patients are given a chance to live by the terrorist organization Sacred Hegemony of Cycle Kindred Evolutional Realm, otherwise known as "Shocker", who relocate them to their island base to convert them into the cyborg Inhumanoids Cobra and Snake.

In the present, Shocker Inhumanoid Bat kidnaps college student Takeshi Hongo to convert and mentally condition him into the Shocker soldier "Hopper". While successfully completing a mission, he meets Shocker's Major Agents, who order him to kill witnesses to their operations, journalist Asuka Midorikawa, and her fiancé Katsuhiko Yano. Amidst an attempt on their lives with assistance from Shocker soldier Spider, Hongo's memories resurface and he fights Spider. However, Yano is killed in the struggle, and Asuka finds Hongo next to his body. Blaming him for Katsuhiko's death, she follows Hongo to figure out why he had changed.

As a result of Hongo's treason, Major Agent Elderly Gentleman has converted the second Hopper and sent him to eliminate their former soldier. While Hongo defeats Spider, Asuka meets a figure who has an uncanny resemblance to Yano, revealing his name as Hayato Ichimonji; instead of killing Hongo, leading to Shocker branding him a traitor as well.

When Bat attempts to kidnap Asuka and turn her into an Inhumanoid, an enraged Ichimonji turns on Shocker and joins forces with Hongo to defeat Bat, Cobra, and Snake at Shocker's base, though Elderly Gentleman and the other Major Agents escape to plan their revenge.

Several actors in this film have appeared in previous Kamen Rider productions. Hiroshi Miyauchi plays Tōbei Tachibana, a character who has appeared in numerous other Kamen Rider shows, acting as a sort of father figure to the Riders. Miyauchi is known for portraying the title character in 1973's Kamen Rider V3. Hassei Takano, who portrays Hayato Ichimonji (Kamen Rider 2) in the film, also starred as Miyuki Tezuka (Kamen Rider Raia) in the 2002 series Kamen Rider Ryuki. Hideyo Amamoto posthumously reprises his role as Dr. Shinigami through archival footage from the original Kamen Rider series.

The crew of The First also features many returning faces. Director Takao Nagaishi is a longtime tokusatsu director who has helmed several episodes of 2006s Kamen Rider Kabuto. Nagaishi was also an assistant director on the original Kamen Rider series. The film was written by Toshiki Inoue, a popular fixture in anime and tokusatsu screen writing. He has written virtually every theatrical film in the Kamen Rider franchise, as well as all the episodes of Kamen Rider Agito (except for one) and Kamen Rider 555. He also served as a writer on Kamen Rider Kuuga, Kamen Rider Ryuki, Kamen Rider Blade, and Kamen Rider Hibiki. Inoue is the son of the late Masaru Igami, who was the chief writer on the original Kamen Rider series, as well as Kamen Rider V3, Kamen Rider Stronger, and New Kamen Rider.

• The movie has a great deal of elements from the original television series that spread across from the beginning to end, although several of these conflict with the film's timing. Hongo Takeshi originally had to ride his motorcycle at high speeds to power his typhoon belt and transform into his Rider form while Ichimonji Hayato was able to power the Typhoon by arm movements. Although Hongo was able to do the same eventually, the movie version can do it from the beginning.
• The Riders' henshin movement is also different from the actual series. In the series, Hongo and Ichimonji perform a series of stylish hand-waving, then jump into the air to complete the transformation. In this movie, they simply open up their leather jackets (or polo shirt, in one of Ichimonji's cases), revealing the Typhoon Belt (and their body armor), then snap on their helmets and faceplates on their heads to transform. These movements are implemented later in the movie, but are mostly just showy poses that have no connection to their transformation.
• Dr. Shinigami appears from the very beginning of the movie, although in the original series, he appeared after the defeat of Colonel Zol, the first Shocker general.
• The character of Hayato Ichimonji was completely rewritten. In the television series, Ichimonji was a photographer who was kidnapped to become Shocker's new Kamen Rider, although he was rescued by Takeshi Hongo before he could be brainwashed; the two were allies from the beginning. In the film, Ichimonji was originally Katsuhiko Yano, the lover of Asuka Midorikawa. Katsuhiko was killed by Spider, and Hongo/Hopper was framed for it. Katsuhiko's corpse was recovered and turned into a cyborg similar to Hongo. His brain was altered to believe he was a man named Hayato Ichimonji in competition for Asuka's affection. Ichimonji originally served as Hongo's enemy, and later a hesitant ally. He disappears at the end of the movie, leaving his helmet on the road.
• Asuka Midorikawa shares the same last name as one of Hongo's professors who had worked for Shocker, Professor Midorikawa. In the original series, it is Professor Midorikawa who saves Hongo before he can be subjected to brain surgery by providing the distraction to allow Hongo to escape, only to ultimately be murdered by the Spider. Asuka also shares a similarity with Professor Midorikawa's daughter, Ruriko; both had witnessed the death of their respected loved ones (Professor Midorikawa for Ruriko, who was her father, and Katsuhiko Yano for Asuka, who was her fiancé) with their own eyes and originally thought that Hongo was to blame for it. The both of them ultimately found out the truth and forgave Hongo.
• The mysterious Great Leader of Shocker is noticeably absent from the film but made a cameo in the film sequel, Kamen Rider The Next, while Dr Shinigami and the other commanders will not appear.

Opening theme

• "Let's Go!! Rider Kick" (レッツゴー！！ライダーキック, Rettsu Gō!! Raidā Kikku)
  • Lyrics: Shotaro Ishinomori
  • Composition & Arrangement: Shunsuke Kikuchi
  • Artist: Koichi Fuji

Ending theme

• "Bright! our Future"
  • Lyrics: ISSA
  • Composition: ISSA & YUKINARI
  • Arrangement: YUKINARI & UNAShinji Tanahashi
  • Artist: Da Pump

The film received a manga adaptation illustrated by Tatsuya Egawa and was serialized in Tokusatsu Ace. However, it became notorious among Kamen Rider fans for its poor quality, which led to Egawa to receive a permanent contract dissolution from Toei after the first chapter was released.

In the 227th episode of the radio show Let's go Manga-chick with Kazuhiko Shimamoto!, Shimamoto, who has done previous works with the Kamen Rider franchise with a Kamen Rider ZO manga and a one-shot manga based on Kamen Rider Black, criticized the author's lack of motivation about the drawings as if were they were preliminary drawings with no background, and the loss of composition. He also criticized the manga's editor for approving the low quality illustrations, quoting, "When I get this manuscript, I'm going to turn my desk over and not take it back".

A sequel was produced in 2007 called Kamen Rider: The Next. The film included the rider Kamen Rider V3, who had his own show in 1973 and served as a sequel to the original Kamen Rider show.

• Official Website at the Wayback Machine (archived 2007-06-11)
• Kamen Rider: The First at IMDb