List of Kamen Rider Ryuki characters

This is a list of characters of the 2002 Kamen Rider Series Kamen Rider Ryuki.

13 Kamen Riders

The 13 Kamen Riders (13人の仮面ライダー, Jūsan-nin no Kamen Raidā) are the central characters of the series. Thirteen Card Decks (カードデッキ, Kādo Dekki) were created for thirteen Kamen Riders. The Riders make Contracts with monsters from the mysterious Mirror World (ミラーワールド, Mirā Wārudo), a parallel dimension opposite to our own in which only the Kamen Riders can exist. The Riders draw on their monsters' strength in exchange for feeding them the life force of the creatures they destroy. The creator of the Advent Cards (アドベントカード, Adobento Kādo) has only one rule: that there can be only one Kamen Rider. The others must be killed, and the sole victor will be granted a single wish, which leads to a conflict known as the Rider War.

Each Rider possesses their own Card Deck that contains the Advent Cards, the V-Buckle (Vバックル, Bui Bakuru) belt which manifests whenever they put the deck up against the reflective surface before sliding the deck into the belt to complete the transformation, and the Ride Shooter (ライドシューター, Raido Shūtā) motorcycle which serves as the Rider's transportation between the real world and the Mirror World. In battle, the Riders uses their Advent Cards in conjunction with their personal card readers called Visors (バイザー, Baisā) to invoke various abilities that draws their strength from their Contract Monsters.

Ryuki: Shinji Kido

Shinji Kido (城戸 真司, Kido Shinji) is a 23-year-old good-hearted, friendly, simple, and naive idealist who works at the ORE Journal as a journalist trainee. He investigates a man named Koichi Sakakibara, whom disappeared, and finds a card deck in Koichi's apartment and eventually encounters a dragon, Dragreder, which attacked him but was then mysteriously repelled. Later that day, he falls into a car window and ends up being dragged to the Mirror World. He was attacked by Dispider then was saved by Ren Akiyama, Kamen Rider Knight. Shinji was told to stay out of the Rider conflict, but he decides to become a Kamen Rider to prevent Mirror Monsters from devouring humans and eventually, he contracts Dragreder and becomes Kamen Rider Ryuki (仮面ライダー龍騎, Kamen Raidā Ryūki) to protect people's lives and stop the Rider War. With the Survive Rekka (烈火) card, the card he received from Shiro Kanzaki, he eventually gains the ability to transform into Kamen Rider Ryuki Survive (仮面ライダー龍騎サバイブ, Kamen Raidā Ryūki Sabaibu). Although he died protecting civilians from a pack of Raydragoons, Yui's death convinces Shiro to negate the Rider War and avert all of the deaths that took place; with most of the former participants, including himself, living normal lives afterwards.

In Kamen Rider Zi-O and its Rider Time: Kamen Rider Ryuki side story, Shinji developed a fear of mirrors when his grudge towards the ORE Journal's clients for not supporting his former workplace created Mirror Shinji and attempted to end his life before Kamen Rider Zi-O helped him accepts his other self and finally move on. Soon after, Shinji ends up being drafted into a new Rider War while slowly regaining his memories as he wins the Rider War and fights Another Ryuki before leaving him to Zi-O and Geiz while honoring Ren's final request to check on Eri.

Shinji Kido is portrayed by Takamasa Suga (須賀 貴匡, Suga Takamasa).

Knight: Ren Akiyama

Ren Akiyama (秋山 蓮, Akiyama Ren) is a 24-year-old cold loner who fights constantly and is frequently unemployed. He received his Card Deck before the start of the series. He accepted Kanzaki's offer to join the Rider war to give his fiancé, Eri Ogawa, a full recovery as she was in a mysterious coma ever since an encounter with Darkwing. Ren later contracted with Darkwing and became Kamen Rider Knight (仮面ライダーナイト, Kamen Raidā Naito). With the Survive Shippu (疾風, Shippū) card, he eventually gains the ability to transform into Kamen Rider Knight Survive (仮面ライダーナイトサバイブ, Kamen Raidā Naito Sabaibu).

In Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story, Ren ends up being drafted into a new Rider War while slowly regaining his memories before dies defeating Asakura, asking Shinji to check on Eri.

Ren Akiyama is portrayed by Satoshi Matsuda (松田 悟志, Matsuda Satoshi).

Zolda

Shuichi Kitaoka

Shuichi Kitaoka (北岡 秀一, Kitaoka Shūichi) is a 30-year-old self-proclaimed "super-lawyer" who tends to only help someone if he has something to gain. Because he has a terminal case of cancer and has been given only a few months to live, he accepted Kanzaki's offer to join the Rider War. His prize is to be immortal so that he could continue his extravagant lifestyle. Because of his illness, he suffers from frequent dizzy spells and fainting. He fights as Kamen Rider Zolda (仮面ライダーゾルダ, Kamen Raidā Zoruda), with Magnugiga as his Contract Monster, though he eventually had Goro take his place during the final days of the Rider War. Though he died, his death was temporary averted once the Rider War ran its course.

During Kamen Rider × Super Sentai: Ultra Super Hero Taisen, the Game World's Kitaoka was chosen by the said world's Masato Jin/Beet Buster into Emu Hojo/Kamen Rider Ex-Aid's team, in term of his contract service. Kitaoka temporarily assumes the form of the green-colored Midorider (ミドライダー, Midoraidā), a hybrid of Midorenger and the Double Riders, once he and his team prevail in the Game World's Ultra Super Hero Taisen tournament. In this form, he rides the Gokaigers' Gokai Galleon against the Xevious fleet. By the events of Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki storyline, Kitaoka passed on with Goro as succeeding him as Zolda.

Shuichi Kitaoka is portrayed by Ryohei (涼平, Ryōhei).

Goro Yura

Goro Yura (由良 吾郎, Yura Gorō) is Kitaoka's 25-year-old loyal servant who is highly skilled with household work and hand-to-hand combat. He is also aware of Kitaoka's activities as a Rider and helps as much as he can. Goro was once Kitaoka's client. Because of that, Kitaoka's condition was not diagnosed in time. Feeling in debt, Goro decided to be his loyal servant and bodyguard forever. He would later serve as the second Zolda, taking over for a dying Kitoka as he died fighting Asakura before being brought back to life when the Rider War's events were averted.

In Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story, Goro is being drafted into a new Rider War and feigns having no memory of the previous Rider War while posing as Asakura's servant until an opportunity to kill him presents itself. Goro gets his chance, but dies inflicting the death wound on Asakura.

Goro Yura is portrayed by Tomohisa Yuge (弓削 智久, Yuge Tomohisa).

Ouja: Takeshi Asakura

Takeshi Asakura (浅倉 威, Asakura Takeshi) is a 25-year-old sadistic and bad-tempered criminal who murdered his entire family during childhood, gaining a reputation for having a love to fight and kill in his random fits of rage. As a result of his sadistic nature, prior to becoming a Rider, Asakura was personally responsible for both ending the piano career of Tezuka's friend Yuichi Saito and the murder of Miho Kirishima's older sister. His arrogant personality resulted with his defense attorney, Shuichi Kitaoka, refusing to represent him and leaving him to rot in jail. Because he was in prison and could not feed his destructive nature, Asakura gladly accepted Kanzaki's offer to join the Rider War and forms a pact with Venosnaker, using his newfound powers as Kamen Rider Ouja (仮面ライダー王蛇, Kamen Raidā Ōja) to break out of jail and get his revenge on Kitaoka, learning of his identity as a Kamen Rider.

Over the series, thanks to Ren helping him fake his death to ensure no interference, Ouja manages to kill off both Gai and Raia, taking their Contract Monsters as his own. But once the police learn he is still alive, Asakura was once more wanted as he attempts to settle things with Kitaoka. By the end of the series, Asakura finally has his showdown with Zolda and defeats him. However, Asakura finds out seconds later that "Zolda" was actually Goro, resulting with him in utter disarray of being denied the right to kill the man he hated the most as he is gunned down by the police before his demise was averted. In the movie's alternate ending, due to Ryuga's intervention during his fight with Femme in the Mirror World, Asakura ends up being dissolved into nothingness after Femme destroys his deck.

In Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story, Asakura is being drafted into a new Rider War and is the only one to retain his memories of the previous Rider War. After being fatally wounded by Goro, Asakura dies after killing Ren.

Takeshi Asakura is portrayed by Takashi Hagino (萩野 崇, Hagino Takashi).

Kamen Rider Odin

Kamen Rider Odin (仮面ライダーオーディン, Kamen Raidā Ōdin) is a mysterious golden entity who fights with his Contract Monster Goldphoenix. Being a sentient Card Deck that Shiro Kanzaki created, provided with host bodies to control, Odin serves as the man's representative in the Rider War while watching over Yui. His powers include teleportation and his ability to rewind time to the beginning of the Rider War via his Time Vent card. Odin possesses incredible strength, the ability to teleport short distances, and the ability to shoot a gust of golden feathers. Odin also possesses powerful cards, namely the Time Vent card that allows him to reverse time to the beginning of the Rider War and the Survive Mugen (無限) card which makes him invincible when used with the Survive Shippu and Survive Rekka cards. Throughout the Rider War, Odin makes brief appearances and fights the other Kamen Riders before he and Knight Survive are left. But after a climatic battle, Odin disappears after Kanzaki sees the pointlessness of the Rider War as it was rendered null and void upon Yui's death.

During the events of Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story, Odin resurfaces and turns Tatsuya Kanō into Another Ryuki to establish a new Rider War for his agenda of resurrecting Yui. Odin battles Kamen Riders Zi-O and Geiz after they defeated his Another Rider, destroyed for good after the Time Riders used the Ryuki and Knight Ridewatches to negate his Survive card combo.

Kamen Rider Odin is voiced by Tsuyoshi Koyama (小山 剛志, Koyama Tsuyoshi) who also provides the voice of the 13 Rider's Visors.

Scissors: Masashi Sudo

Masashi Sudo (須藤 雅史, Sudō Masashi) is a 28-year-old unscrupulous detective using his job to cover up his illegal activities disposing of any witnesses to his acts. He had a partner, the older Tomoyuki Kaga (加賀 友之, Kaga Tomoyuki) who owned the antique and collection shop, until the older man's demand for a bigger cut in the profit made Sudo kill him, plastering him into the wall of his own shop seconds before Kanzaki appeared and offered him a Card Deck explaining the terms of accepting it. Sudo took it gladly and made his contract with the Mirror Monster Volcancer, becoming Kamen Rider Scissors (仮面ライダーシザース, Kamen Raidā Shizāzu) and playing a part in the disappearances as he feeds his victims to Volcancer. He and Kamen Rider Knight confronted each other once prior to the series, neither aware of each other's identity.

Reiko's investigating of Kaga's shop after finding a link between it and some of the missing people made her a target of Sudo as he manages to hospitalize her. Shinji is then sent to continue in her place, confronting Scissors in the Mirror World before Ren saves him. Though both believed Scissors to be Kaga, Shinji acts against Ren's wishes to befriend Scissors. This results in Sudo tricking Shinji into giving his name, Knight's human identity and Yui's address as he attempts to kill the Riders while kidnapping Yui to have leverage over her brother. By then, both Ren and Reiko realized the truth behind Kaga's death as Sudo decides to kill everyone to cover his tracks. In the course of his battle with Knight, Scissor's Card Deck cracked as a result of the two using their Final Vents on each other, after Knight hits his deck first. This resulted with Volcancer devouring its master in an ironic death by betrayal.

While Sudo's death is later averted once the Rider War comes to an end, he is succeeded as Scissors by Ishibashi in Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story.

Masashi Sudo is portrayed by Takeshi Kimura (木村 剛, Kimura Takeshi).

Raia: Miyuki Tezuka

Miyuki Tezuka (手塚 海之, Tezuka Miyuki) is a 24-year-old mysterious and enigmatic fortune-teller who believes in predestination, another Kamen Rider that Kanzaki did not personally pick to have a Card Deck. The real chosen one was his friend Yuichi Saito (斉藤 雄一, Saitō Yūichi), an excellent pianist who lost ability to play when a mugger (later revealed to be Takeshi Asakura) broke his hands. After his friend was devoured by a Guldthunder after refusing Kanzaki's offer to fight in the Rider War, Tezuka takes the Card Deck on his behalf and becomes Kamen Rider Raia (仮面ライダーライア, Kamen Raidā Raia) to avenge his friend by ending it. While trying to convince Ren that he has no chance of winning due to his self-doubt, Tezuka meets Shinji and becomes their ally. Kanzaki would later attempt to escalate the battle by giving Tezuka one of two Survive cards, but he passes it to Ren instead. Tezuka would later avenge Yuichi by destroying Guldthunder before being killed by Ouja later on after taking a fatal hit meant for Ryuki in an act of defying fate.

Miyuki Tezuka is portrayed by Hassei Takano (高野 八誠, Takano Hassei).

Gai: Jun Shibaura

Jun Shibaura (芝浦 淳, Shibaura Jun) is a 21-year-old 2nd year college student at Meirin University, extremely well versed in computers and programming to be in the Matrix netgame club. Being the son of a company president, Shibaura is arrogant in personality and toys with other people's lives for nothing more than a good laugh. He joined the Rider War simply to be the winner as it was all a game to him, transforming into Kamen Rider Gai (仮面ライダーガイ, Kamen Raidā Gai).

Manipulating his fellow members into killing each other in a game, Shibaura meets Shinji and later steals his Dragreder card from him to use both it and the virus he uploaded to the ORE Journal mainframe to become the head of their company. But Shimada's own hacking skills and Tezuka foiled Shibaura's plans as he is arrested soon after. However, his father was able to bail him out with Kitaoka's aid. After learning the other Riders' identities, Shibaura kidnaps Yui to start a "Rider party" between him, Knight, Raia, and Ryuki. However, in the middle of the fight, their battle gets intertwined with the one between Zolda and Ouja, who used Gai as a shield to take the brunt of Zolda's Final Vent before killing him with his own hands.

Jun Shibaura is portrayed by Satoshi Ichijo (一條 俊, Ichijō Satoshi).

Verde: Itsuro Takamizawa

Itsuro Takamizawa (高見沢 逸郎, Takamizawa Itsurō) is the main antagonist of Kamen Rider Ryuki Special: 13 Riders, which takes place in one of the alternate continuities in the Ryuki timeline, a 38-year-old rich and charismatic businessman of the Takamizawa Group who is able to transform into the chameleon-themed Kamen Rider Verde (仮面ライダーベルデ, Kamen Raidā Berude) with the aid of his Contract Monster Biogreeza. He joined the Rider War to add to his already massive wealth so he could take control of the world.

In Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story, Takamizawa is absent with Kimura taking his place as Verde.

Itsuro Takamizawa is portrayed by Arthur Kuroda (黒田 アーサー, Kuroda Āsā).

Tiger: Satoru Tojo

Satoru Tojo (東條 悟, Tōjō Satoru) is a 25-year-old disturbed man with a twisted moral background; a social outcast determined to do whatever it takes to be accepted. However, Tojo also seemed to have a great amount of respect for his teacher, Hideyuki Kagawa, adopting his theories on the concept of heroism, although Tojo develops a hero syndrome due to his bloodthirsty nature. Due to Tojo's history of mental instability, he came to believe that he needed to kill those he loved or cared about to become a hero, as his grief would make him fight harder. Becoming Kamen Rider Tiger (仮面ライダータイガ, Kamen Raidā Taiga), Tojo aided Kagawa on the goal to close the Mirror World. However, killing Kagawa because of his ideologies, Tojo joined the Rider War to prove himself as a true hero and to prove that his twisted version of Kagawa's ideals are correct.

However, these actions result in a downward spiral of contradictions for Tojo as he tries to win by any means, from betraying Sano to an attempt to trap the other Riders in the Mirror World by destroying their only way out. But as he runs off from committing the latter, Tojo saw a father and son, briefly reminding him of Kagawa and his own child. However, a truck was about to crash into the two, and Tojo sacrificed himself to save them at the cost of his own life. Ironically, the following day, a newspaper featured an article on Tojo's good deed and labeled a hero.

While Tojo's death is later averted once the Rider War comes to an end, he is succeeded as Tiger by Totsuka in Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story.

Satoru Tojo is portrayed by Jun Takatsuki (高槻 純, Takatsuki Jun).

Imperer: Mitsuru Sano

Mitsuru Sano (佐野 満, Sano Mitsuru) is the 21-year-old son of a wealthy businessman who worked in a parking garage, occasionally cleaning rich people's cars, although he came from an affluent family. His father sent him out into the world so that he could learn the hardships of life and not be spoiled by a rich upbringing. Because of his poor lifestyle, he believed friendship, respect, and love could be bought, and thus accepted Kanzaki's proposal to become Kamen Rider Imperer (仮面ライダーインペラー, Kamen Raidā Inperā) in order to become rich and lead a happy life. He became a mercenary of sorts, attempting to sell his strength as a Kamen Rider to the various factions within the remaining Riders.

After seeing he cannot worm out of being a Kamen Rider after finally inheriting his father's business and having no more need to fight, Sano decides to buy the services of the other Riders to fight his battles for him. But the attempts ended in failure before he decides to team up with Tojo and befriended him. However, after being back-stabbed by Tojo and left for dead, Sano attempted to get back to the real world when he was ambushed by Ouja, who destroys his Card Deck. Unable to leave the Mirror World, Sano screams for help as he dissolves within minutes.

While Sano's death is later averted once the Rider War comes to an end, he is succeeded as Imperer by Ishida in Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story.

Mitsuru Sano is portrayed by Takashi Hyuga (日向 崇, Hyūga Takashi).

Femme: Miho Kirishima

Miho Kirishima (霧島 美穂, Kirishima Miho) is a character who only appeared in one of the alternate continuities detailed in Kamen Rider Ryuki: Episode Final, an 18-year-old con-artist who seduces wealthy men in order to steal their money and/or valuables. Miho accepted Kanzaki's proposal to join the Rider war for two reasons: she wanted to resurrect her sister and take revenge on her killer, Takeshi Asakura. She fights as Kamen Rider Femme (仮面ライダーファム, Kamen Raidā Famu) to reach this goal, in which she succeeds in defeating Asakura, but is killed by Mirror Shinji when he exploited her love for Shinji. She is the first official female Kamen Rider.

Miho Kirishima is portrayed by Natsuki Katō (加藤 夏希, Katō Natsuki).

Ryuga: Mirror Shinji

In the alternate continuity of the Ryuki timeline depicted in Kamen Rider Ryuki: Episode Final, Yui Kanzaki had already met and befriended Shinji Kido when they were still both very young. As a result, the young and lonely Yui subconsciously created a duplicate of Shinji in the imaginary Mirror World. The Mirror World version of Shinji Kido, referred as "Mirror Shinji Kido" (鏡像の城戸 真司, Kyōzō no Kido Shinji), could survive indefinitely in his own universe without any extra protection, but could only stay in the real world for a short time before starting to disintegrate, just like how a normal human would in the Mirror World. Several years later, the doppelganger adopts the identity of Kamen Rider Ryuga (仮面ライダーリュウガ, Kamen Raidā Ryūga) and joins the Rider War in order to pursue his goal of becoming a real person in the real world. After killing Miho, the Mirror Shinji attempts to merge with Shinji in order to survive, but the real world Shinji forces him out and fights him, resulting in his death due to a match between their long duel, and a clash of two Final Vents.

In Kamen Rider Zi-O and its Rider Time Ryuki side story, a main universe version of Mirror Shinji was created as an embodiment of Shinji's darkest aspects when he constantly blamed readers of the ORE Journal for their part in his workplace's disbandment. While briefly employed by the Time Jackers until Shinji accept him, Mirror Shinji becomes his universe's version of Kamen Rider Ryuga and attempts to absorb Shinji and before Ren and Shinji forced him out of the latter's body with Ryuki defeating him.

Takamasa Suga portrays Mirror Shinji Kido as well as Shinji Kido in a dual role.

Abyss

Kamen Rider Abyss (仮面ライダーアビス, Kamen Raidā Abisu) is a shark-themed Kamen Rider who appears as Femme's replacement in the second Rider War during the events of Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story, the Kamen Rider introduced in an alternate reality depicted in Kamen Rider Decade. He can combine his Contract Monsters Abysslasher and Abysshammer into the giant shark Abyssodon (アビソドン, Abisodon).

Abyss is voiced by Yasunao Sakai (坂井 易直, Sakai Yasunao), while his civilian identity portrayed by Kenji Tominaga (富永 研司, Tominaga Kenji).

Kanzaki family

Yui Kanzaki

Yui Kanzaki (神崎 優衣, Kanzaki Yui) is a 19-year-old woman who had been aiding Ren prior to the series. Yui's purpose for joining Ren is to find clues about her long lost brother Shiro. But unbeknownst to her, she has a mysterious connection with Mirror World and its monsters.

Yui Kanzaki is portrayed by Ayano Sugiyama (杉山 彩乃, Sugiyama Ayano).

Sanako Kanzaki

Sanako Kanzaki (神崎 沙奈子, Kanzaki Sanako) is Shiro's and Yui's 45-year-old aunt who is the owner of coffee shop Atori (花鶏). She took an immediate dislike for the hard as nails Ren, but welcomed the clumsy Shinji with open arms. Sanako considers herself to be a wise woman and says that her intuition is never wrong.

Sanako Kanzaki is portrayed by Kazue Tsunogae (角替 和枝, Tsunogae Kazue).

Shiro Kanzaki

Shiro Kanzaki (神崎 士郎, Kanzaki Shirō) is the 25-year-old mysterious man and scientific genius who created the Kamen Riders for the purpose of creating the Rider War, with Kamen Rider Odin as his right-hand man. He is Yui's older brother, who was taken to live with his relatives in America thirteen years prior to the start of the series. While researching the Mirror World, Kanzaki was claimed to be killed, but in reality, he merged with his Mirror World double to survive in the Mirror World, then he created the Kamen Riders and developed the ability to reverse the flow of time. Though cruel, Kanzaki's intent for the Rider War was to prevent Yui from dying on her twentieth birthday. At the end of the series, Kanzaki honors his sister's wishes and uses his time manipulation powers to change history so that Yui remains dead, thus negating the Mirror World and Rider War and all the deaths that occurred because of them.

Shiro Kanzaki is portrayed by Kenzaburo Kikuchi (菊地 謙三郎, Kikuchi Kenzaburō).

ORE Journal

ORE Journal, stands for "Open Resource Evolution", is an online journal resource where Shinji Kido worked as a journalist trainee.

Daisuke Okubo

Daisuke Okubo (大久保 大介, Ōkubo Daisuke) is the 36-year-old chief editor and Shinji's senior. He can be a bit silly at times.

Daisuke Okubo is portrayed by Kanji Tsuda (津田 寛治, Tsuda Kanji).

Reiko Momoi

Reiko Momoi (桃井 令子, Momoi Reiko) is a 24-year-old no-nonsense reporter whose goal is to uncover the truth behind the disappearances that are inextricably linked to the Rider War. She also became Kitaoka's target for unwanted affections.

Reiko Momoi is portrayed by Sayaka Kuon (久遠 さやか, Kuon Sayaka).

Nanako Shimada

Nanako Shimada (島田 奈々子, Shimada Nanako) is a 25-year-old computer programmer who works for the ORE Journal.

Nanako Shimada is portrayed by Hitomi Kurihara (栗原 瞳, Kurihara Hitomi).

Megumi Asano

Megumi Asano (浅野 めぐみ, Asano Megumi) is a 25-year-old woman who used to be Kitaoka's secretary. She returned into his life claiming that the two of them were to be married. Megumi is a strong individual and quite capable in a fight, which is why Kitaoka hired her as his bodyguard. However she is quite ditzy, which was why Kitaoka had fired her. She would later be hired by Okubo as a journalist for ORE.

Megumi Asano is portrayed by Chisato Morishita (森下 千里, Morishita Chisato).

Alternatives

The Alternatives are Pseudo-Riders (擬似ライダー, Giji Raidā) created by Hideyuki Kagawa and based from Shiro Kanzaki's blueprints of the 13 Kamen Riders; their purpose is to close the Mirror World. Satoru Tojo, Kamen Rider Tiger, then joined the duo only to betray them and kill them.

Hajime Nakamura

Hajime Nakamura (仲村 創, Nakamura Hajime) is a 27-year-old graduate student at Seimeiin University. He was originally one of the staff under Professor Ejima at Lab 401, but he was sick the day Kanzaki and Ejima began their experiments. Upon learning what occurred, Nakamura never forgave Kanzaki and his sister, for the events that occurred. Nakamura studiously avoided any questions about the lab, Kanzaki and what happened there, when encountered by Yui when she came to Seimeiin University to learn more about her brother's actions and later Reiko and Shinji (though Kagawa had given him some superficial explanation). Nakamura eventually joined Professor Kagawa to stop the Rider War as Alternative (オルタナティブ, Orutanatibu). However, Nakamura's reasons were for vengeance and thus was killed by Tojo because of those reasons.

Hajime Nakamura is portrayed by Junichi Mizuno (水野 純一, Mizuno Jun'ichi).

Hideyuki Kagawa

Hideyuki Kagawa (香川 英行, Kagawa Hideyuki) is a 37-year-old professor at Seimeiin University who has his wife Noriko (典子) and son Yuta (裕太, Yūta). Prior to Kanzaki's experiment, Kagawa wandered into Lab 401 one day and happened to see Shiro Kanzaki's notebook lying on the floor. He scooped it up, opened it and gave every intriguing page a once-over glance before Kanzaki snatched it from him. However, Kagawa had photographic memory and remembered what he had read. After learning the severe nature of Kanzaki's experiments, yet by his own admittance does not fully understand what is happening, Kagawa began to duplicate Kanzaki's work in order to close the Mirror World. To that end, he formed a relationship with Satoru Tojo and Nakamura. Kagawa eventually created the Alternative Decks, eventually using one himself to become Alternative Zero (オルタナティブ・ゼロ, Orutanatibu Zero).

Hideyuki Kagawa is portrayed by Satoshi Jinbo (神保 悟志, Jinbo Satoshi).

Mirror Monsters

The Mirror Monsters (ミラーモンスター, Mirā Monsutā) are entities from the Mirror that were created by Yui as childhood drawings she and her Kanzaki made which were given life by Yui's mirror-self. As these creatures have no true life of their own, they prey on humans to survive on their lifeforce by dragging them into the Mirror World to feed. Most Mirror Monsters normally do not harm Yui, but some that make the attempt are dispatched by Kamen Rider Odin or a Mirror Monster loyal to Kanzaki. The Contract Monsters (契約モンスター, Keiyaku Monsutā) used by the Kamen Riders are also Mirror Monsters, serving as their respective rider's power source in return for absorbing the energy of a defeated Mirror Monster. But if the energy is not absorbed, it reforms into a new Mirror Monster. Despite some Contract Monsters willing to attack their Kamen Riders if not properly fed or the contract become null and void, some display a sense of loyalty in avenging their master by going after their killer.

Dragreder (ドラグレッダー, Doragureddā)

A red mechanical Japanese dragon Contract Monster under Ryuki, later gained enough power to evolve into Dragranzer (ドラグランザー, Doraguranzā). Its dark counterpart is Ryuga's Contract Monster Dragblacker (ドラグブラッカー, Doraguburakkā).

Darkwing (ダークウイング, Dākuuingu)

A giant mechanical vampire bat-like Contract Monster under Knight, later gained enough power to evolve into Darkraider (ダークレイダー, Dākureidā).

Volcancer (ボルキャンサー, Borukyansā)

A mechanical humanoid crab-like Contract Monster under Scissors, using its large claws to fight. Voiced by Yoshimasa Chida (千田 義正, Chida Yoshimasa).

Magnugiga (マグナギガ, Magunagiga)

A giant Minotaur-like robot that is Zolda's Contract Monster. Likely due to the size of the costume, it never fights on its own and is only summoned for Zolda's Final Vent.

Evildiver (エビルダイバー, Ebirudaibā)

A flying mechanical stingray monster that was originally Raia's Contract Monster, serving as a glider Raia rides on for ramming attacks, later becoming Ouja's Contract Monster.

Metalgelas (メタルゲラス, Metarugerasu)

An armored humanoid rhinoceros monster that was originally Gai's Contract Monster before Ouja acquired it.

Venosnaker (ベノスネーカー, Benosunēkā)

The largest of the Mirror Monsters, it is giant mechanical cobra monster with acidic spit that is Ouja's Contract Monster. After Ouja acquired Evildiver and Metalgelas, he uses the Unite Vent card to merge them with Venosnaker to form the dragon-like Genocider (ジェノサイダー, Jenosaidā) whose breastplate can produce a black hole.

Destwilder (デストワイルダー, Desutowairudā)

An armored humanoid white tiger monster that is Tiger's Contract Monster.

Gigazelle (ギガゼール, Gigazēru)

Humanoid gazelle monsters that are Imperer's Contract Monsters, often accompanied by Megazelle (メガゼール, Megazēru), Negazelle (ネガゼール, Negazēru), Omegazelle (オメガゼール, Omegazēru), and Magazelle (マガゼール, Magazēru). Prior to Imperer's appearance, the gazelle monsters were wild Mirror Monsters and still have traces in occasionally attacking Imperer while summoned to support him.

Goldphoenix (ゴルトフェニックス, Gorutofenikkusu)

A mechanical phoenix monster that is Odin's Contract Monster.

Biogreeza (バイオグリーザ, Baiogurīza)

A humanoid chameleon monster that is Verde's Contract Monster.

Blancwing (ブランウイング, Buran'uingu)

A mechanical swan monster that is Femme's Contract Monster.

Psycorogue (サイコローグ, Saikorōgu)

A robotic humanoid cricket monster that is Alternative Zero's Contract Monster and can transform into a motorcycle called the Psycoroader (サイコローダー, Saikorōdā). Survived its master upon being controlled by Yui, it was weakened by Ryuki to be destroyed by Knight.

Abysshammer (アビスハンマー, Abisuhanmā)

A hammerhead shark monster with machine guns and missile launchers that was a wild Mirror Monster during the first Rider War before it was destroyed by Ryuki and Zolda. During the second Rider War depicted in Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki side story, Abysshammer becomes one of Abyss's Contract Monsters.

Abysslasher (アビスラッシャー, Abisurasshā)

A shark monster with two saw-like swords and water-spewing abilities that was a wild Mirror Monster during the first Rider War before it was destroyed by Knight Survive. During the second Rider War depicted in Rider Time: Kamen Rider Ryuki, Abysslasher became one of Abyss's Contract Monsters.

Others

Eri Ogawa

Eri Ogawa (小川 恵里, Ogawa Eri) is the 24-year-old fiancé of Ren Akiyama who ended up in a coma when attacked by Darkwing the moment Kanzaki opened a link to the Mirror World, with Ren participating in the Rider War so he can reawaken her while making regular visits to her hospital room. Ren succeeds in reviving Eri once named the winner of the Rider War by default, though he died from his injuries soon after with the Rider War's events are averted soon after.

By the events of Kamen Rider Zi-O's Rider Time: Kamen Rider Ryuki storyline, Eri works as a nurse in the hospital she was placed at during her coma.

Eri Ogawa is portrayed by Mahiru Tsubura (つぶら まひる, Tsubura Mahiru).

Hitoshi Ejima

Hitoshi Ejima (江島 均, Ejima Hitoshi) is a former professor at Seimeiin University, he was the one who help Kanzaki perform the experiment that resulted with Eri's coma. Since then, Ejima left the university and wandered the city with a Seal card in hand to protect himself from the Mirror Monsters. But once he loses the card, Ejima ran back to his lab to plea Kanzaki to help him as he's attacked by a Terabiter. Though saved from the monster, Ejima dies of a heart attack as he sees Yui and laments that she should have never been born.

Hitoshi Ejima is portrayed by Senzaburo Makimura (牧村 泉三郎, Makimura Senzaburō).

Koichi Sakakibara

Koichi Sakakibara (榊原 耕一, Sakakibara Kōichi) is a 28-year-old man who lives in an apartment where Shinji found a Card Deck that leads him to become Kamen Rider Ryuki. He disappeared prior to the start of the series, eaten by Dragreder. In Kamen Rider Ryuki Special: 13 Riders, Sakakibara is the original Ryuki before the latter passes his deck to Shinji as he dissolves inside the Mirror World.

Koichi Sakakibara is portrayed by Keiichi Wada (和田 圭市, Wada Keiichi).