What Could Have Been / Kamen Rider

General

• As with its sister franchise Super Sentai, many DX drivers ship with unused sounds referring to collectibles and crossovers that don't exist in the final shows, either because they were scrapped or as a case of anticipating events that might occur but aren't set in stone. The latter demonstrated itself in Kamen Rider Drive with Super Dead Heat, an unused sound byte in the Drive Driver and Mach Driver that would later be used by the Mach Driver to refer to both Drive's movie form and Mach's novel form.
• The franchise almost had a crossover with Batman. DC artist Jerry Robertson met Ishinomori in Japan in the 90s at an art exhibit featuring his work, and was interested in a collaboration of the two properties after having a conversation with Ishinomori. Sadly it went nowhere due to Ishinomori's worsening health meaning he couldn't devote the time to help seriously bring the idea to life.

Kamen Rider (1971)

• Orginally Kamen Rider was supposed to be an adaptation of Skull Man, Executives however considered it far too bleak for television. Shotaro then started to retool it under the name of "Cross Fire" until his son showed him a picture of a grasshopper man. Taking inspiration from this is when Kamen Rider was born.
• Before becoming the squid-themed Ikadevil, Doctor Shinigami's One-Winged Angel form was planned as the saw shark-themed Girizames. Ultimately, Girizames appeared as another Monster of the Week in episode 67, the episode preceeding Doctor Shinigami's last stand.
• It was indeed planned that Kazuya Taki, the Riders' Badass Normal ally, become Kamen Rider 3, the idea being that he would have been captured by Shocker and converted into a cyborg to fight Hongo, only to escape just like his predecessors. An alternate idea also suggested at the time was Rider 1 and 2 creating a new robotic Kamen Rider 3 to join them in their battle. The idea of turning Kazuya into a Rider seemed to get close enough to execution that he was depicted as such in the contemporary manga Kamen Rider: Rider 3 vs. The Demon of General Black.

Kamen Rider V3

• The introduction of the third Kamen Rider was initially planned for the original series. What ultimately became the first two episodes of Kamen Rider V3 were first conceived as episodes 99 and 100.
• Shiro Kazami's name was originally planned to be Shiro Hayabusa, this was changed during a meeting as the producers did not want confusion with the similarly named Hayabusao, a horse from the show Henshin Ninja Arashi.
• Guillotine Saurus and Poison Needle Spider were, in addition to Cannon Buffalo, created for The Movie; it was only due to an agreement with the network that it was arranged that they appear on TV first, serving as dual MOTWs in #20 and #21 before being brought Back from the Dead.
• Introduced halfway through the series, Interpol agent Ken Sakuma was devised as a successor to the original series' Badass Normal Kazuya Taki, but failed to meet projections when he abruptly disappeared by the end of V3's third quarter.
• Riderman was supposed to have a machinegun arm as one of his arsenal. While Shotaro Ishinomori already made its concept art, he ultimately dropped the idea. It did. however, finally get to appear in Kamen Rider Taisen.
• The prospect of Riderman leading his own show following V3 was considered but dropped in favor of introducing a new Rider. All we have left of that is a Development Gag in OOO’s 999th episode special, which counted Riderman as a show complete with a mock title card.

Kamen Rider X

• Ryo Hayami (Keisuke Jin) previously fell just short of landing the lead part in Tetsujin Tiger Seven, a P Productions tokusatsu hero show which would only conclude its broadcast six weeks after X had premiered, thus making it likely that, had he been successful earlier, another actor would have been cast as the new Kamen Rider.
• In the wake of Apollo Geist's defeat, it was originally planned to introduce a new G.O.D. executive named Black Mars. However, the unforseen popularity of Apollo Geist changed the course of the series and this character was scrapped in favor of reviving Apollo Geist.
• Bat Rasputin was a concept for a Villain Monster to feature in the TV series which was changed to Bat Franken, the Monster of the Week in The Movie.
• Much like what would later benefit Dengeki Sentai Changeman, X was originally slated for only 33 episodes but was afforded an extra two due to delays in the production of Kamen Rider Amazon.

Kamen Rider Amazon

• What ultimately became Amazon was originally conceived by Shotaro Ishinomori as "Dragon Rider". Inspired by Bruce Lee, who was nicknamed "Dragon", Dragon Rider would have been a kenpo master. Dragon Rider would have fought monsters whilst travelling, having no Home Base / Local Hangout like his predecessors and the vast majority of his successors, a concept which would be used for Kamen Rider Stronger.

Kamen Rider Stronger

• Shigeru Araki was offered a choice between the eponymous role of Stronger and Akaranger in Himitsu Sentai Gorenger. Due to the established nature of Kamen Rider, he chose the former while the role Tsuyoshi Kaijo, the very first lead of Super Sentai, would go to Naoyo Makoto.
• As noted on the main page, Tackle is not officially considered a Kamen Rider. Had she been officially recognized as one, Stronger would have been the first Kamen Rider series with a female lead Kamen Rider - a distinction another series ended up having 41 years later.
• According to Word of God from Producer Toru Hirayama, had the show gotten a 52-episode run, they would've revived Tackle - meaning that by extension, the much-despised Kamen Rider Curse (which saw most of the female riders during the Heisei era either die or be de-powered) likely wouldn't exist.

Kamen Rider (Skyrider)

• Series producer Toru Hirayama offered the role of Hiroshi to former child actor Mitsunobu Kaneko of Giant Robo fame but declined citing his need to work at his job. Had he accepted it, he would have been among the first Kamen Rider stars to have died early since his death in 1997.
• The ninth Kamen Rider was initially conceived as being named Kamen Rider V9 ala his predecessor V3. In reaction to declining ratings, V9 was originally planned to be introduced within this series as an additional hero to Skyrider similar to Rider 2 and Riderman. Ultimately, however, the return of the Seven Legendary Riders in the second half successfully increased viewing figures, thus the ninth Rider was remade to succeed Skyrider in a new show, becoming Super-1.

Kamen Rider Super- 1

• Hiroyuki Watanabe, who would later go onto play Gaoh, and Shun Sugata, who later became Kamen Rider ZX, unsuccessfully auditioned for the titular character's role^note the role of Kazuya Oki, not the role of suit actor. Similar to Masaya Matsukaze and Kamen Rider Kuuga, had either one of them gotten the role, it's very easy to imagine that they would've been willing to reprise the role, considering that the former reprised his role as Gaoh in the second Kamen Rider Battride War game, and the latter reprised his role as Ryo Murasame in Kamen Rider Taisen, and neither faces the legal issues that Shunsuke faces.

Kamen Rider ZX

• The TV special was intended to generate interest for an ongoing ZX TV series, but nothing came out of it, and it wouldn't be until 3 years later that another Kamen Rider series would air.
• At one point Mitsunobu Kaneko who is most famous for playing Daisaku Kusama/Johnny Sokko in the live action Giant Robo toku from the 60's auditioned to play the role of Eisuke Mikage but his father made him turn down the role.

Kamen Rider Black RX

• The kaijin Death Garon was planned initially as an RX version of Shadow Moon, hence design similarities.
• There were plans for a new season after Black RX for a 1990 airing but it was scrapped as it was decided to put the franchise on an indefinite hiatus from television and continued with stageshows and three films, which explains why there was no seasons airing in the Nineties. Ryohei Kobayashi auditioned for the season and after it was scrapped, he was cast as Fumiya Hoshikawa in Chikyuu Sentai Fiveman as compensation.

Shin Kamen Rider: Prologue

• Had the film received sequels, Shin would "evolve" into a more Kamen Rider-like form (A belt and armor).
• The idea is even seen in some other series. In the first episode of Black, Kotaro turns into a form that's pretty monstrous for a little while before completing the transformation; his Transformation Sequence continues to feature the "Grasshopper Man" for a brief flash before the helmet forms. Agito also features the monstrous "Another Agito" as someone whose 'evolution' into an Agito is not as complete as our main hero's. Those series stop short of this level of Body Horror, but provide an idea of what might have been planned for Shin once the "prologue" this film was intended as was over and his journey began in earnest.

Kamen Rider ZO

• According to an interview with the director, Keita Amemiya, ZO was originally intended to continue into a TV series, much like Kamen Rider ZX, but due to various reasons, those plans never continued. It's possible that what was left of these plans were recycled into the following Kamen Rider J.

Kamen Rider J

• J was originally intended to be a sequel to ZO and J himself was meant to be ZO's upgraded form (hence their similar designs).
• Ryujin◊ was a monster, designed by Keita Amemiya for J, who ultimately did not appear.

Kamen Rider Kuuga

• Shotaro Ishinomori died while writing the concept for Kamen Rider Kuuga. Suppose he had lived - how different would the end result have been? Would we have still gotten the other Heisei era shows, or would other shows have been made instead?
• A theatrical sequel to the TV series languished in Development Hell because the writers couldn't come up with a satisfactory conclusion to the story. Production was canceled in 2006, leaving Kuuga the only Heisei Rider series without a theatrical movie.
• The early designs for Ultimate Kuuga had a much more regal (and gold) aesthetic. These would end up influencing the design of Kiva's Emperor Form and Kuuga's Rising Ultimate Form in Decade.
• Masaya Matsukaze auditioned for the title role, but was ultimately passed over for Joe Odagiri. Considering he's been in multiple Super Sentai series, it's easy to imagine that Matsukaze would have been far more willing to reprise his role in later productions than Odagiri. At the very least he would likely have returned for video games like Battride War, since he became a voice actor starting with Shenmue.

Kamen Rider Agito

• Shinichiro Shirakura's proposal for the 2001 Kamen Rider was humans using cards to form contracts with monsters, which would be realized for the next year with Ryuki.
• There was an idea for the series to feature 10 Kamen Riders, which would be reused in Ryuki.
• As noted on the main page, Agito was originally intended to be a sequel to Kuuga, but the writers of the latter series objected, stating that doing so would have made Godai's battles meaningless.
• At Japan Worlds Heroes 2017, Noboru Kaneko, who would later play GaoRed, mentioned that he auditioned for both the title role and Makoto Hikawa.
• Yusuke Kosaka, the son of X-Rider lead Ryo Hayami and his co-star Naoko Miyama, was famously in the final selection in the auditions for Agito only to be rejected when his connection to an earlier Rider actor was found out.
• The original concept for G3-X would've had him wielding a riot shield, which ultimately didn't become part of his arsenal.
• Although both Kuuga and Kamen Rider Agito were very successful, Agito was originally planned on being the final Kamen Rider series. Then the 9/11 terrorist attacks occurred, and it was decided to continue the franchise so kids would have a show to teach them about justice.

Kamen Rider Ryuki

• As acknowledged above, the Contract Monsters were first proposed by Shinichiro Shirakura for what would ultimately became Agito. Also, what became Ryuki was not always going to be a Kamen Rider. One proposal was a knight hero based on "Cross Fire", one of the original plans for the first Kamen Rider, as a revival of the then dormant Metal Heroes franchise.
• When it was decided to follow Agito with another multi-Rider show, one proposal had a whopping 50 Riders'.
• Even when the setting of 13 Riders was settled, it was uncertain that all of them would appear. For instance, Ouja would have been introduced as having defeated two Riders off-screen, before things changed so that Gai and Raia could materialize in the show proper.
• Two unused Rider forms exist: Raia Survive, and a form that (presumably) Yuichi Sato would've transformed into had he contracted with Guldthunder like Shiro intended^note whether he was supposed to become a Rider originally or this was just produced for the sake of "What if" is unknown. The unused Rider's name, coincidentally, was Blade, predating the series of the same name by around two years.
• Tamotsu Shinohara designed additional Mirror Monsters Begazelle and Igazelle, whom ultimately did not appear.

Kamen Rider 555

• A few elements that never made it to final production of Kamen Rider 555 include three unused riders◊.
• According to Kento Handa, there is a scene between him and Yuria Haga in the Paradise Regained movie that they had disagreements with, so they successfully convinced the producers and director to change it. It is believed by some fans that this specific scene was the sex scene between Takumi & Mari, which the final product depicts with their Orphnoch forms rather than as humans.

Kamen Rider Blade

• Magazine stills showed that Toei actually filmed an official Spinoff Sendoff sequence between 555 and Blade where Takumi Inui literally passes the baton to Kazuma Kenzaki, then the two transform side-by-side. One can't help but wonder if this would have lead to Kamen Rider having annual baton-passing scenes as its sibling franchises Super Sentai and Pretty Cure do (though it's mostly been rendered a moot point by the Movie Taisen crossovers).
• In-Universe, each of the 52 normal Undead is pretty much this. Each had the chance to be the one whose species could've ruled the Earth, the Human Undead just managed to win out. This includes lions, tigers, spiders, grasshoppers, and even some species of plants. Yeah, Orchids could've ruled the world.

Kamen Rider Hibiki

• Hibiki was originally to show Asumu becoming an Oni in the final episode, along with Kiriya. A suit had been put together for him, but due to extensive Executive Meddling, the scenes weren't included in what became the rewritten ending, and Asumu's Oni suit was scrapped for parts to enhance Kiriya's. This is partially remedied in the Hibiki's World episodes of Kamen Rider Decade, where Hibiki dies and Asumu becomes an Oni in his place.
• Hibiki could apply for this all around, thanks to the Executive Meddling that afflicted its latter portion and forced them to focus on selling toys more than telling a story.

Kamen Rider Den-O

• Den-O artbooks showed that early costume designs included a Rider based off of mythical Japanese hero Yamato Takeru, as well as two villain Riders with matching asymmetrical costumes (IE one right-side and one left-side) who could merge into a single Rider — potentially the inspiration for Double. Additionally, the monster design artbook Say Your Wishshowed some of Yasushi Nirasawa's unused designs, including a Hydra Imagin and a team of four inspired by the Town Musicians of Bremen.
• Promotional images for The Onigashima Battleship showed a Ryutaros-possesed Ouja wielding the GX-5 Cerberus Minigun, presumably loaned to him by an Urataros-possessed G3. As the aforementioned minigun does not show up, either this was an oversight by the promoters^note as the Cerberus is wielded by Kamen Rider G3-X, not the regular G3, or at one point, it was planned to have G3-X appear instead of G3.

Kamen Rider Decade

• Early rumors for Decade were that the series was to have a high school theme and have actor Kousei Amano reprise his role as Tachibana/Garren from Kamen Rider Blade. It's likely these ideas were planned at some point, since Kamen Rider Fourze (also an anniversary series) is set in a high school and features Amano in a main role.
• For All Riders vs. Daishocker, there were plans for Riderman to have an updated costume in the same style as the ones from Kamen Rider the First and The Next^note Riderman being the only rider from both the original and V3 to not appear at all in those films, but because it wasn't finished in time they simply had Gackt play the untransformed Joji Yuki and used the original 1973 costume for the big fight scene. The Blaster Arm he uses in the film is just one of several designs made for this; there were also designs for a Blade Arm, a new version of the classic Power Arm, and a generic "Cassette Arm" (which might have just been its default form). Most interestingly, the Power Arm concept art shows it being activated via a Rider Card, suggesting that they're the source of his power (which makes sense, given that this version of Yuki invented the Decadriver and Diendriver).
• Rikiya Koyama was invited to reprise his role as Joe the Haze in the World of Black RX arc but declined.

Kamen Rider Double

• As testified by head writer Riku Sanjo and producer Hideaki Tsukada, Double was conceived during the run of Kiva and was infact planned initially to follow that series in mid-January of 2009 as normal but was pushed back when Decade was thrown into the mix, Decade's purpose being to celebrate ten years of the Heisei Kamen Rider revival as well as having a reduced episode count allowing future Rider shows to premiere in the fall, balancing Super Sentai premiere time in spring, thus Double marked the beginning of the next stage of the franchise.
• Double was originally going to take place in Suito, a flooded city a la Venice. The idea was scrapped and eventually replaced with the much less budget-consuming (and ecologically-correct) "windy city" of Fuuto. In addition, concept art shows that the title character was meant to wear a trench coat.
• As revealed in an interview with producers Hideaki Tsukada and Shinichiro Shirakura, the Fuuto P.I. series came about after a plan for a "Joker City" V-Cinema, which was to bring back Renn Kiriyama as Shotaro Hidari, sadly did not work out.

Kamen Rider OOO

• Giru, the Kyoryu^note Dinosaur Greeed, went as far as having a voice-only cameo in the OOO part of Movie War Core only to never manifest in the TV series itself, with the Dinosaur Greeed instead being a form assumed by Dr. Maki (and Eiji). Giru was voiced by Kenji Hamada, who would be recast as Poseidon in Movie War Mega Max.
• OOO was supposed to have Dr Maki be the villain of the second arc and then be killed off around episode 30, with Ankh as the final villain of the series. Instead, Maki is the final villain and Ankh sacrifices himself to give Eiji his Core Medals.
• Date was also supposed to die, be revived as a homunculus (much like Nobunaga in Movie Wars Core) and become a Greeed. The producer has also confirmed that she wasn't originally planning for Eiji to turn into a Greeed, but changed this later on.
• Eiji was conceived as a more cynical type of character akin to Takumi from Kamen Rider 555. The characterization was changed after Shu Watanabe was cast in the role and it was felt he would fit better as a Nice Guy hero akin to Yusuke Godai from Kuuga.
• The original plan was for Hina to be revealed as an amnesiac Kyoryu Greeed, which would’ve explained her Super-Strength.

Kamen Rider Fourze

• Early pre-release info for Fourze stated that the Kamen Rider club would investigate the legends of Kamen Riders in their town, with guest appearances from past heroes. This got as far as Fourze's Early-Bird Cameo in the Kamen Rider OOO movie (where Gentaro leaves suddenly because he's late for club activities) but the producers later confirmed it had been scrapped because the idea was too much like Decade (and possibly Gokaiger as well). Instead, the club functions to support Fourze, with Shout Outs to previous heroes but no guest stars.
• The character of Hayami/Libra Zodiarts was originally slated to appear for only a few episodes, but his run in the show was later extended. The same thing happened with Bishop from Kamen Rider Kiva, whose character was kept on due to his popularity with fans.
• Hayami was intended to have been given a backstory in which he was a brilliant college student who attracted Gamou's notice. This was eventually cut from the show, but stills of the deleted scene were released in a magazine feature.
• Nadeshiko Misaki was to have been named Yuriko after Tackle, the first (albeit unofficially considered so) female Kamen Rider; but they changed the name in honor of the national women's football team Nadeshiko Japan, which at that time had just won the FIFA Women's World Cup. Her Rider Kick is also based on the kick that scored the winning goal.
  • Appropriately enough, Nadeshiko's actress is now married to a member of the Japanese men's team.

Kamen Rider Wizard

• Medusa almost was played by Hikari Kajiwara, who previously starred in Kamen Rider Blade as Amane Kurihara (and cameoed in Kamen Rider Fourze as the Altar Zodiarts, Ritsuko Usaka), but for unknown reasons, the role went to Erina Nakayama.
• Hacking the DX WizarDriver and White Wizard Driver revealed a number of Wizard Rings were ultimately were not produced. These include Barricade, Confuse (There is an unintelligible equivalent on White Wizardriver), Control, Dark, Delicious, Ear (same for both versions), Eye, Flash, Gamble (Surprise), Happy Birthday, High Speed (Rush; there is however a Rush sound on the regular Wizardriver), Invisible (exclusive to White Wizard; Equivalent to Clear which has no toy and is thus inaccessible), Knock, Note, Perfume (Aroma), Poison, Psychokinesis (same for both versions), Seal (There is an unintelligible version on White Wizardriver) and Shut Up (Silent).
• In addition to these, the DX Wizardriver also has The Origin and The End sounds. The former is activated by scanning the DX Change, Explosion, or Final Strike Wizard Rings (and also the Mage (Amber, Blue, and Green ver.) and Sorcerer Change ring from the "Last Hope Ring Set" and "Wizard Ring Finale Set", respectively) on the DX Wizardriver or Wizar Sword Gun. The latter can be triggered via the Eclipse ring from the "Last Hope Ring Set".

Kamen Rider Gaim

• The team behind Gaim at first played with the idea of a bird/insect theme to the suit designs, until toy company Bandai insisted on fruit. They also considered the idea of having all the Rider suits be samurai with a different kanji on each helmet; but then decided this "wasn't enough", and instead based the suits on different historical armour designs from around the world. They still kept the bird motifs though, as some Riders look like a bird, while one of the Rider's forms looks like a dinosaur (hey, they count as birds).
• Gaim’s production team stated that they hadn't planned on Kaito Kumon gaining an upgrade; but chose to give him his Lemon Energy form because of his popularity with fans.
  • In addition, Zack wasn't even supposed to be a Rider at all. Like Kaito's case, he only got one because he's so popular among the fans.
• Gaku Matsuda, who played Zack in Gaim, stated in an interview that the producer had originally told him Zack was going to be killed off after his fight with Kaito in episode 45. However, he then received the script for the following episode, showing that plans had been changed and Zack would survive.

Kamen Rider Drive

• In concept art, Heart's Roidmude form had golden wings attached to his back.
• Hacks from the Drive Driver and the Shift Brace revealed five unreleased Formula-styled Tire Exchange Shift Cars: F00, F04, F05, F06, and F07. They were likely removed from production lines to preserve the Lucky Number Seven/Rule of Three standings for Type Tridoron.
• The same can be said for the Mach Driver, where hacks found four unreleased Signal Bikes: Ittsu, Yukkuri, Tousan, and Kattobi. They were likely removed to preserve the Super-1 Mythology Gags that they compose around Mach.
• Also, hacking the DX Drive Driver revealed, among other things, sound effects for shift cars of the Toqgers and Toqger Ressha, suggesting that at one point, a crossover might've been planned between Drive and Ressha Sentai ToQger. However, the idea was likely dropped due to Toqger already having crossed over with Drive's predecessor, Gaim. There's also a shift car sound effect for Super Sentai in general, suggesting that at one point, it was planned to have Tridoron combine with Shurikenjin using a Shift Car instead of an OtomoNin Shuriken, which is what ended up happening, similar to what happened with Wizard when he joined up with the Kyoryugers in Super Hero Taisen Z.
• Not to mention some of the Shift Cars not getting used to show their Shift Tires and half of those that did only got names for their Type Tridoron fused combo Shift Tires.
• Unused DX Drive Driver sounds indicate that all of Drive's forms and Heart/Type Miracle were supposed to receive individual upgrades. The soundbyte for Dead Heat's upgrade, Super Dead Heat, would later be used to refer to Drive's Clipped-Wing Angel movie form and Mach's One-Winged Angel novel form.
• Kamen Rider Lupin was devised as a recurring adversary who would face Drive across his movies, which is why the Sequel Hook of him surviving his debut was added in the first place. However, future movies could not accommodate him, and so his story was wrapped up in a DVD Bonus Episode.
• In-universe, Gou would've gotten an upgrade had he not declined after regaining his confidence. Also in a reverse way, Type Tridoron wasn't a planned upgrade form for Drive after Type Formula.

Kamen Rider Ghost

• Ghost's introduction in the Kamen Rider Drive movie Surprise Future showed his battles looking very different: he floated along the ground and the helmet's face lit up. This had been changed by the time of his own show.
• A Leonardo da Vinci Eyecon was supposed to be released as part of a movie-only set of Eyecons for Movie Wars Genesis, and was advertised. Ultimately, this release was cancelled; possibly because of poor sales of movie-exclusive toys in recent years. Instead, the Eyecon was packaged with a Hyper Battle DVD.
• Magazine scans showed images of Alia fighting as Dark Necrom P on Earth, but these scenes ultimately weren't aired.
• Impressively for Super Hero Time, hacking the DX Ghost Driver revealed a sound for only one unrealized Eyecon, Ganbarizing. Both Ex-Aid and Build would realise a trinket based on the arcade game in their toyline, with the former even playing a role in an on-screen spin-off.
• In addition, hacking the Proto Mega Ulorder revealed sounds for other Ganma Eyecons which Igor did not use on-screen. These included the remaining MOTWs^note Katana, Yari, Denki, Insect, Planet, Gazai, Katchu and Hikoki, Commando, Assault^note Which is confusing, since Assault is the generic Ganma body without a unique Parka. Curiously, there are no sounds for the advanced bodies, Superior and Ultima. and Gundari.
• What's also impressive is that, of the existing Ghost Eyecons, almost all of them are canon. While a handful of luminary Damashii were exclusive to Ganbarizing, their Eyecons were among the 100 in The Movie, then the Shinsengumi Eyecon's Damashii was exclusively unveiled in a stage show. The remaining Eyecons are Santa, whose Damashii is Ganbarizing exclusive thus averting An Ass-Kicking Christmas on the show, one based on Kamen Rider creator Shotaro Ishinomori which never had an official Damashii form designed for it. Though the first ten Heisei Rider Damashii were exclusive to Ganbarizing, the only Legend Rider Eyecon not to make it on-screen is the Showa Rider Eyecon, a variant of the Kamen Rider 45 Eyecon.

Kamen Rider Ex-Aid

• In the original script, Emu was supposed to have a big sister who played games with him and wanted to become an idol despite her fragile body. The writers didn't include the aforementioned big sister because they noted that she's a blatant Expy of Karen Hojo from The iDOLM@STER franchise, which Yuya Takahashi is a fan of. Coincidentally, Emu's surname is the same as Karen's, probably as a tribute to her.

Kamen Rider Build

• The Scorpion and Gold Fullbottles originally advertised in catalogs were never released, and their place was taken by the Rose and Helicopter pair.
• Hacking pin combinations on the Build Driver reveals a handful of Fullbottles and Best Matches that were never released, most notably F1Saurus (Kyōrū/dinosaur & F1), CupEnergy (Cupmen/cup ramen & Energy Drink), and CrocodiCon (Crocodile & Remocon/remote control), the last of which had collectible devices released that could access the combination but not standard Fullbottles. In addition quite a few Legend Rider-themed sounds were never used.
• Meanwhile, several Bottles work in the Evol-Driver in combination with the Rider System Evolbottle, implying that Evol would have used them to access new forms. These are Tank, Lock, and Dinosaur (presumably equivalent to the nonexistent Kyōrū Fullbottle).
• And while we got to see a Best Match used in the Evol-Driver in the form of Kamen Rider Mad Rogue, the Evol-Driver actually has sounds for every Best Match. What a different Best Match, such as RabbitTank, would have resulted in is anyone's guess.

Kamen Rider Zi-O

• The producer of Kamen Rider Zi-O has stated publicly that at one point he wanted Tsukasa Kadoya, who returned as a semi-regular character, to be the final villain of the show - it's possible he would have been Another Decade, which ultimately was given to Swartz.
  • Speaking of Zi-O, the third Heisei Generations movie, Heisei Generations Forever, was going to make its US debut on Anime Expo 2020, but due to the COVID-19 pandemic, it debuted online instead.

Kamen Rider Zero-One

• When Kamen Rider Zero-One was first announced, publicity material stated that Aruto's father had died from an illness and Aruto had wanted to become a comedian to cheer him up. By the time the show aired, this had been changed to Aruto being raised by the HumaGear version of his father since early childhood. What happened to his human father isn't mentioned, although one episode shows Aruto's parents to have died on the same day when he was a few months old, suggesting they were killed in an accident.
• The Workplace Competition arc wasn't part of the original plan, which would have saw Aruto losing Hiden Intelligence to Gai Amatsu at the end of the first arc and presumably lead into the Hiden Manufacturing arc. However, because Producer Omori insisted on Aruto staying president of Hiden Intelligence, Takahashi was forced to change his plans and insert in the Workplace Competition arc.
• COVID completely shut down filming, delayed production of the movie from mid show to post show and cut several episodes off the total run time, leading the staff to scramble to rewrite the entire finale to lead into a film, make use of all the new Rider suits they'd already built (specifically Zero-Two and Ark-One) and provide a dramatically satisfying finale. What we got was Aruto using Zero-Two for a whopping two episodes, only to become the villainous Ark-One in grief and rage after Horobi kills Is. Suffice to say this was all NOT the original plan. Promotional art for this early arc showed Zero-Two fighting Ark-One and it was mentioned that Is was not planned to die and they only did so because the film gave them a way to restore her after the series concluded. Exactly what the actual original plan was has yet to be stated, whether Is was supposed to always have been Zero-Two fighting to save Aruto from himself (a similar scene briefly happens in the film) or Zero-Two was supposed to be Aruto's proper final form and Ark-One was someone else.

Kamen Rider Saber

• It was revealed in the FigureOh Magazine after the series ended that, because of the pandemic, Toei staff were forced to scrap a lot more initial ideas than usual.
  • The members of Sword of Logos weren't initially supposed to be friendly like in an actual swordsmen guild, but were at odds with one another, and would be located in different parts of the World of Saber.
  • Touma is a talented novelist in the actual series. But he would have been initially an expert swordsman, and would learn to cross his skills to become stronger and save Luna. He would also remember her, as in the actual series, he was amnesiac and didn't remember how he got his Rider powers.
  • The series would be the tale of Touma going in a Pokémon-like (or for the franchise instance, Kamen Rider Fourze-like) adventure to fight and befriend each of the swordsmen before ultimately fighting a greater threat together.
    • The reason why the pandemic affected this particular aspect of the plot was due to Toei not wanting Riders to fight too often. While it was originally planned to be a darker series, in the wake of the pandemic, Toei wanted to teach children bravery in the face of a worldwide crisis.

Kamen Rider Revice

• An idea which made it to early promotional material had Kamen Rider Revice take place in a world where the past Kamen Riders existed as TV shows ala Heisei Generations Forever and Hikonin Sentai Akibaranger. In the end, it was decided to stick with the Gokaiger-style Shared Universe so as to make crossovers like the Early-Bird Cameo in Saber's Special Issue easier to do.
• Head writer Hanta Kinoshita has stated that he intended for the Igarashi family to have a widowed single mother, but through the planning process it was decided there should be a father present.
• Junya Komatsu had auditioned unsuccessfully for Kamen Rider three times before landing the role of Hiromi Kadota, his first try being all the way back in 2013 (presumably for a role in Gaim).

Kamen Rider Geats

• Early promotional material stated that Neon was the daughter of celebrity parents and unsure whether she still wanted to be famous. By the third episode, this had changed to her parents being the owners of a huge corporation, and Neon being famous as an influencer which her mother is pressuring her to quit.

Kamen Rider Gotchard

• At the start of the show, writer Keiichi Hasegawa stated in an interview that Minato was intended to be an ordinary character who would not become a Rider. This later changed to have Minato become the fourth user of Kamen Rider Dread.

Adaptations

• While most people know (but don't talk about) Saban's Masked Rider, what isn't as well known is that they apparently attempted to adapt Kamen Rider a second time. Power Rider was a trademark that was filed in 2011. It became a large subject of speculation, in part due to the source material for Power Rangers Samurai having a crossover with Decade. However, as of January 2014, the trademark was abandoned, meaning either Saban chose not to do anything with it, or they were only filing it to prevent other people from using the idea.
  • Most of the speculation guessed it would be either Decade (to adapt the Samurai crossover), Double (which was more recent, and was believed to be easier to adapt), or OOO (which was the most recent, and had the most merch potential)^note although it's also possible that Fourze was the show in mind, given that said trademark was filed 2 months before the start of said show, and they decided if they would adapt it based on what happened in said show.
  • On the topic of American adaptations, Kamen Rider Dragon Knight has a few attached to it:
    • The producers originally wanted to adapt another series (depending on the source you look at, it was either 555 or Blade, although some sources also say Kabuto was considered), but chose Ryuki for the merch potential. Had Dragon Knight done better, it's likely that one of the passed-over shows would've been picked up.
    • A throw-away line in Power Rangers: Dino Thunder jokes about the idea of Tommy Oliver (the black ranger of that show) being Batman^note the context being that an item in his study would reveal a hidden cave. Tommy's actor, Jason David Frank, almost got to be the American Tokusatsu equivalent of Batman - Kamen Rider Wing Knight - as he auditioned for the part of Len (who holds the Wing Knight deck); however, as the producers didn't want people to think the show had any Power Rangers connections, they went with Matt Mullins instead.