Category:Dopants

The Dopants (ドーパント, Dōpanto?) are the fictional antagonists in the Kamen Rider Series Kamen Rider Double. Dopants are normal humans who use Gaia Memories. The Gaia Memories are aspects of the true Gaia Memory (地球の記憶, Chikyū no Kioku?), the knowledge of everything on the Earth. These were originally accessed due to Philip's link to the Gaia Memory by means of the Gaia Library (地球（ほし）の本棚, Hoshi no Hondana?). But after he was taken from them, the Sonozaki Family uses a strange temple underneath their mansion to access the Gaia Memory. They then sell these to the highest bidder or to common criminals, both types used as guinea pigs to study the Gaia Memories as part of the Gaia Impact project. The name comes from the English words "dopant" and "doping".

Dopant Gaia Memories
A Gaia Memory (ガイアメモリ, Gaia Memori?) is a mysterious device resembling a USB flash drive that contains all of the Earth's knowledge of what it represents. This enables its user to become a Dopant, or in some special cases a Kamen Rider. Every Gaia Memory is adorned with the first letter of its name, stylized to reflect the powers it imbues on its user. For example, the Injury Memory (acquired by Shotaro and Philip before the series begins) resembles a broken bone in the shape of the letter I. Each Memory also features a button which when clicked causes the Memory to loudly declare its name; while this is traditionally done immediately before inserting the Memory by Riders and Dopants alike, it is unclear if it is actually mandatory to activate the Memory's powers. In order to transform into a Dopant, the Gaia Memory is first inserted into a device called the L.C.O.G (Living Connector Setting Operation Gun (生体コネクタ設置手術器, Seitai Konekuta Setchi Shujutsu Ki?)), also called a Connect Shooter (コネクトシューター, Konekuto Shūtā?), which then produces a USB port-like tattoo on the user's skin called a Living Connector (生体コネクタ, Seitai Konekuta?). Whenever the Gaia Memory is pressed onto the Living Connector, it enters the user's body and transforms the user into a Dopant. Use of a Gaia Memory without a Living Connector is possible, but the side effects of doing so are nearly fatal.

This direct insertion will eventually drive its user insane from its addictive influence, which is why special belts called Memory Drivers (メモリドライバー, Memori Doraibā?) have been developed for use by high ranking members of the Museum to filter out these and other side effects. This weakens the Dopant visibly; high-ranking Museum members use some of the strongest Gaia Memories to more than compensate for this weakening.

To defeat a Dopant, a Kamen Rider has to use one of his Maximum Drive (マキシマムドライブ, Makishimamu Doraibu?) finishing attacks to eject and destroy the Gaia Memory, resulting in what is called a Memory Break (メモリブレイク, Memori Bureiku?). Evolved Gaia Memories require a direct strike on its location within the Dopant's body to execute the Memory Break without the risk of killing the user. If the Dopant does not have a Living Connector, a Memory Break will not occur, however the Gaia Memory will still be ejected from the user's body. In order to defeat a Dopant that uses a Memory Driver, the belt must be broken in order to defeat the Dopant and cause the Memory Break.

In the movie Double Forever, the Dopants use T2 Gaia Memories, 26 special Gaia Memories developed by Foundation X based on Fumine Sonozaki's findings. Though originally in the possession of Jun Kazu before giving it to another member of the Foundation to take to their headquarters, the T2 Gaia Memories end up in the possession of mysterious terrorist group NEVER. Unlike the original Gaia Memories, these memories appear to have some sentience, injecting themselves into people who are compatible with them (Watcherman and Santa-chan) or causing a Living Connector to appear on someone's skin (Queen). Other than their leader, each member of NEVER uses a T2 Gaia Memory based on one of Kamen Rider Double's Gaia Memories.

Other Gaia Memories seen, yet not used in the series include Finger (フィンガー, Fingā?), Lightning (ライトニング, Raitoningu?), Key (キー, Kī?), Umbrella (アンブレラ, Anburera?), Gravitation (グラビテーション, Gurabitēshon?), Apple (アップル, Appuru?), Star (スター, Sutā?), Dog (ドッグ, Doggu?), Injury (インジャリー, Injarī?), Crab (クラブ, Kurabu?), Orange (オレンジ, Orenji?), Time (タイム, Taimu?), Zero (ゼロ, Zero?), Jazz (ジャズ, Jazu?), Ear (イア, Ia?), Music (ミュージック, Myūjikku?) Hell (ヘル, Heru?), You (ユー, Yū?), Pyramid (ピラミッド, Piramiddo?), and Ocean (オーシャン, Ōshan?), and Injured Memory (picture on phillip computer)

In the real world, special edition Kamen Rider Gaia Memory Toys feature not only Gaia Memories used in the series but also Gaia Memories that features Kamen Riders, the Imagin Momotaros, and limited edition Gaia Memories like the Ganbaride Gaia Memory and the CycloneJoker Televikun Gaia Memory.

Anomalocaris
The childish Genzo Takamura works as the head of one of the many Gaia Memory manufacturing centers scattered throughout Futo. As the Anomalocaris Dopant, he can travel underwater, fire his fangs as if they are bullets, and transform into a giant form called the Big Anomalocaris. Due to the fact that councilwoman Miyabi Kusuhara is continuing her late husband's plans to build the Second Futo Tower and Ryubee Sonozaki sees it as a threat to his enterprise, Takamura is given the order to assassinate her. After giving a proto-model of his Anomalocaris Memory, a production-model, to his friend so he can serve as a decoy, Genzo later kidnaps the councilwoman's daughter Asuka to lure her mother into a trap. However, the Anomalocaris Dopant is defeated by Kamen Rider Double. A member of EXE transforms into an Anomalocaris Dopant but was defeated by Kamen Rider Joker.
 * Statistics
 * Identity: Genzo Takamura(first),unnamed EXE member(second)
 * Gaia Memory: Anomalocaris Memory
 * Actor: Takaaki Ito
 * Episodes: 5-6, 49
 * Memory Break: Kamen Rider Double CycloneJoker's Joker Extreme (Prototype), Double LunaTrigger's Trigger Full Burst, Kamen Rider Joker's Rider Punch

Cockroach
Ikari is a sociopathic dōjinshi artist who runs the Dark Bug Exterminator website, a blog where people write down the names of those they want dead and he carries out the deed as the Cockroach Dopant, writing about his adventures in his self-published manga as the hero "Gokistar". His Dopant abilities include the ability to climb along walls and to move faster than oncoming attacks, much like a cockroach. Only Kamen Rider Double LunaTrigger's homing attacks are able to hit him, but with his speed he steals the Luna, Trigger, Heat, and Metal Memories from Double. Ikari then decided to take the rest of Double's arsenal to become more powerful. However, after Philip learns the Heaven's Tornado dance and uses it against the Cockroach Dopant, the Gaia Memories are retrieved and a defeated Ikari is left for the police. A member of EXE transforms into a Cockroach Dopant but lacked the speed and manuverability as Ikari and was defeated by Kamen Rider Joker's Rider Kick.
 * Statistics
 * Identity: Ikari (first), unnamed EXE member (second)
 * Gaia Memory: Cockroach Memory
 * Actor: Jin Katagiri
 * Episodes: 7-8 (first)
 * Memory Break: Kamen Rider Double LunaTrigger's Trigger Full Burst, Kamen Rider Joker's Rider Kick

Sweets
Yukiko Sasaki is a maid at the Sonozaki estate with a sweet tooth that she cannot satisfy, only able to be a food critic instead of a pâtissière because she could not cook very well. In her Dopant form, she is able to fire a whip cream that hardens like cement to trap her enemies. As the Sweets Dopant, Yukiko kidnaps the the top pâtissiers hired by the Sonozaki family by dragging them in her "Sweets Cream" state to a small building on the grounds to make pastries only for her. However, when Akiko attempts to weed out the wrong culprit with her sweets, Yukiko kidnaps her with Mai Asakawa, the daughter of her previous victim. Though intending to kill Akiko for disgracing her love for sweets, the Sweets Dopant is battered by Akiko using a chair before Kamen Rider Double finishes her off.
 * Statistics
 * Identity: Yukiko Sasaki, Unnamed Chef (W Returns)
 * Gaia Memory: Sweets Memory
 * Actor: Maha Hamada
 * Episodes: 9-10, Kamen Rider W Returns: Eternal Chapter
 * Memory Break: Kamen Rider Double HeatJoker's Joker Grenade, CycloneJoker's Joker Extreme (W Returns)

Another Sweets Dopant was encountered in Kamen Rider W Returns with the pre-production Sweets Memory used by a gourmet chef that made him go insane until he was defeated by Kamen Rider Double.

Virus
The Virus Memory normally enables the user to unleash a plague that can wipe out an entire city, yet is weak against fire-based attacks. The Memory came into the possession of Sachi Yamamura, shortly after she saw that her fiance was a con man who uses women. While on her way home, having second thoughts about using it to exact her revenge, she is run down by a car driven by a group of thugs. Before she is hit, she uses the Gaia Memory but becomes comatose before the transformation completes. However, her consciousness enters a wrecked SUV which is rebuilt and she uses her brother's emotions to make him drive the SUV to take revenge on the thugs until Kamen Rider Double destroys the SUV. She then uses the Virus Dopant's physical form to chase after her fiance, becoming consumed by the Gaia Memory, until it is destroyed by Kamen Rider Double.
 * Statistics
 * Identity: Sachi Yamamura
 * Gaia Memory: Virus Memory
 * Actor: Rinako Matsuoka
 * Episodes: 11-12
 * Memory Break: Kamen Rider Double HeatTrigger's Trigger Explosion

Violence
Tsuyoshi Ageo is Wakana's manager, a spineless man who loves her in spite of the abuse. Ageo is used by Wind Wave DJ Motoko Saeki in a scheme to force Wakana off the air, giving him the Violence Memory she bought. Overcome by the Memory's influence, Ageo assumes the alias of "Mister Question", targeting certain places of value to Wakana and portraying himself as a stalker. As the brutish Violence Dopant, his left arm is strong enough to destroy anything in its path, even enough to smash through cars. He can compress his body into a wrecking ball-like form called the Violence Ball to cause more collateral damage. Once found out, the Violence Dopant points Wakana to Motoko before Double defeats him.
 * Statistics
 * Identity: Tsuyoshi Ageo
 * Gaia Memory: Violence Memory
 * Actor: Hiromichi Miyoshi
 * Episodes: 13-14
 * Memory Break: Kamen Rider Double LunaTrigger's Trigger Stag Burst

Arms
Kenji Kurata, part of the Twin Rose (ツインローズTsuin Rōzu? ) burglar team with partner Fuyumi Aso (麻生 冬実 Asō Fuyumi? ), is hired by Saeko to lure Philip out of hiding. Given the Arms Memory, it turns Kurata into a uncontrollable sadist as he turns his back on Fuyumi and the morals they followed. Able to morph his left forearm into a variety weapons such as a sword, the Arms Dopant goes on a burglary spree and claims to be a Kamen Rider to force Double into the trap, only able to capture Shotaro and Akiko to use as hostages. However, the unexpected return of Kamen Rider Double FangJoker, and eventual control of the form, turns the tables as the defeated Kurata is left for the police.
 * Statistics
 * Identity: Kenji Kurata (倉田 剣児 Kurata Kenji? )
 * Gaia Memory: Arms Memory (アームズメモリ Āmuzu Memori? )
 * Actor: Kōichirō Nishi (西 興一朗 Nishi Kōichirō? )
 * Episodes: 15-16
 * Memory Break: Kamen Rider Double FangJoker's Fang Strider

Kenji Kurata is portrayed by Kōichirō Nishi (西 興一朗, Nishi Kōichirō?).[9] He previously portrayed Ryouga Hakua in Bakuryū Sentai Abaranger.

Bird
Akane is a middle school girl selected by Saeko to test the limits of one of the newest Gaia Memories: the Bird Memory. In addition to the fact that no one under the age of 20 is allowed to use a Gaia Memory, the Bird Memory can also be used by those without a Living Connector and it has an addictive side effect. When Akane runs away from home, her friend Touma is the first to test the true powers of the Bird Memory out and decides to use it for fun with Yuichi and Yayoi until Touma decides to use it to attack people. They are stopped by Kamen Rider Double, and the two boys are taken into the hospital after suffering from some of the negative side effects of using a Gaia Memory without a Living Connector. Later, Akane is overpowered by withdrawal from the Bird Memory and attacks Philip who gets in her way of obtaining it. Consumed completely by the Gaia Memory, Akane is able to access the Bird Dopant's Strengthen Form (強化態 Kyōkatai? ), only to be defeated after the Nasca Dopant assists Kamen Rider Double in finding the Bird Dopant's weak spot for a direct strike on the Bird Memory.[10]
 * Statistics
 * Identities: Akane Egusa (江草 茜 Egusa Akane?, 18), Touma Fujikawa (藤川 統馬 Fujikawa Tōma? , 17), Yuichi Kanamura (金村有一 Kanamura Yūichi? , 17), Yayoi Kubota (久保田 弥生 Kubota Yayoi? )
 * Gaia Memory: Bird Memory (バードメモリ Bādo Memori? )
 * Actor: Mana Konno (今野 真菜 Konno Mana? ), Haruki Kimura (木村遼希 Kimura Haruki? ), Takuya Yoshihara (吉原 拓弥 Yoshihara Takuya? ), Manami Ikura (伊倉 愛美 Ikura Manami<sup style="line-height: 1em; ">? )
 * Episodes: 17-18
 * Memory Break: Kamen Rider Double FangJoker's Fang Strider (Touma), Double CycloneTrigger's Trigger Bat Shooting (Akane)

IceAge
Originally only known as the icy Dopant (氷のドーパント, Kōri no Dōpanto?), the IceAge Dopant has the ability to make absolute zero ice from attacks to clones. Kiyoshi was the son of flower coordinator Makiko Katahira (片平 真紀子, Katahira Makiko?), who received bad press due to her son's actions. Obtaining the IceAge Memory, Kiyoshi uses it to attack anyone who makes him mad such as Shotaro when he unintentionally shoved Kiyoshi out of the way while looking for Makiko. After his clone was destroyed by Accel, believing the Dopant to be the one he is looking for, Kiyoshi runs into his mother as she takes the Gaia Memory from him to take the blame for the attack. However, Shotaro uncovers the truth as IceAge Dopant is defeated and Ryu Terui arrests Kiyoshi instead of killing him in revenge, only to learn that Kiyoshi is not his target.
 * Statistics
 * Identity: Kiyoshi Katahira (片平 清 Katahira Kiyoshi<sup style="line-height: 1em; ">? )
 * Gaia Memory: IceAge Memory (アイスエイジメモリ Aisueiji Memori<sup style="line-height: 1em; ">? )
 * Actor: Kento Shibuya (渋谷 謙人Shibuya Kento<sup style="line-height: 1em; ">? )
 * Episodes: 19-20
 * Memory Break: Kamen Rider Accel's Dynamic Ace

Kiyoshi Katahira is portrayed by Kento Shibuya (渋谷 謙人, Shibuya Kento?).<sup class="reference" id="cite_ref-10">[11] He previously played Tsutomu Tsumura in Kamen Rider Hibiki.

Triceratops
Aya Kujo is a former FPD officer who transfered to the LAPD under encouragement from her partner Masaki Mizoguchi, whom she loved. After the scrunity and disappearance of Mizoguchi, Aya returns to Futo and purchases the Triceratops Memory in order to take revenge against the men responsible for Mizoguchi's disappearance and death: the crooked cops Himuro and Ken Akutsu. As the Triceratops Dopant, she possesses superhuman strength, can generates spheres of plasma, and uses the Dinosaur Club (ダイノソアクラブ, Dainosoa Kurabu?) as her weapon. However, after killing off Himuro and Akutsu, Aya's revenge shifts to Futo as the Gaia Memory's corruptive powers begin to take hold. She eventually gains the ability to transform into a giant bipedal Triceratops called the Big Triceratops (ビッグ・トライセラトップス, Biggu Toraiseratoppusu?) before Kamen Rider Accel stops her with his new Gunner A support robot.
 * Statistics
 * Identity: Aya Kujo (九条 綾, Kujō Aya?)
 * Gaia Memory: Triceratops Memory (トライセラトップスメモリ, Toraiseratoppusu Memori?)
 * Actor: Ayumi Kinoshita (木下 あゆ美, Kinoshita Ayumi?)
 * Episodes: 21-22
 * Memory Break: Kamen Rider Accel's AccelGunner Gaia Cannon

Aya Kujo is portrayed by Ayumi Kinoshita (木下 あゆ美, Kinoshita Ayumi?).<sup class="reference" id="cite_ref-11">[12] She previously portrayed Marika "Jasmine" Reimon in Tokusou Sentai Dekaranger.

Liar

 * Statistics
 * Identity: Sachio Sawada
 * Gaia Memory: Liar Memory (ライアーメモリ, Raiā Memori?)
 * Actor: Moro Morooka (モロ 師岡)
 * Memory Break: Kamen Rider Double CycloneJoker's Joker Extreme

Sachio Sawada (沢田 さちお, Sawada Sachio) is a street calligrapher and poet who uses the Liar Memory to become the Liar Dopant (ライアー・ドーパント, Raiā Dōpanto), referred to in urban legends as the Radio Tower Clown (電波塔の道化師, Denpatō no Dōkeshi). Armed with the Lie Speaks (ライスピークス, Rai Supīkusu), a staff with a large speaker in a shape of a giant mouth that can shoot energy projectiles, the Liar Dopant's signature move is converting any lie he says into his Lie Needles (ライニードル, Rai Nīdoru), forcing whoever it hits to fall under the Dopant's deception. Though he is paid by Yukiho to help Jimmy win the Fuuuuuutic Idol (フーティックアイドル, Fūtikku Aidoru) competition, he turns on her after she fails to pay him his ideal amount, revealing the ruse in front of Jimmy. Once his cover is blown, and his being a fan of Wakana's radio show used against him, the Liar Dopant is defeated through the combined powers of Kamen Riders Double & Accel, with Double dealing the Memory Break using CycloneJoker's Joker Extreme.
 * Episodes: 23-24

Puppeteer
Keio Horinouchi (堀之内 慶應, Horinouchi Keiō?) is a children's author who has gained commercial success for his book The Girl and the Dollhouse (少女と人形の家, Shōjo to Ningyō no Ie?) which he wrote to reflect his feelings for his daughter Rikako who died several months ago. As the Puppeteer Dopant (パペティアー・ドーパント, Papetiā Dōpanto?), he uses special puppet strings to take control of whatever he wishes and carries a flute that produces super-sonic waves. He uses these powers to take revenge against those who give his book harsh criticism by controlling his daughter's doll, Riko, as the instrument of his vengence. After being exposed, getting a new puppet in Wakana by Isaka, Horinouchi turns his attention towards Akiko before being defeated by Kamen Rider Double CycloneMetal's Metal Twister Maximum Drive.
 * Statistics
 * Identity: Keio Horinouchi
 * Gaia Memory: Puppeteer Memory
 * Actor: Wataru Shihoudou (四方堂 亘, Shihōdō Wataru?).
 * Memory Break: Kamen Rider Double CycloneMetal's Metal Twister
 * Episodes: 25-26

Invisible
Lily Shirogane (リリィ白銀, Riryi Shirogane?) is a popular magician trying to follow in her grandfather Frank's footsteps. To emulate his most popular trick, the disappearing lady, Lily is given the Invisible Memory by Dr. Isaka, turning her into the Invisible Dopant (インビジブル・ドーパント, Inbijiburu Dōpanto?). Unbeknownst to her, Isaka modified the Invisible Memory such that she does not turn into a monstrous Dopant and making it impossible to remove from her body. She initially goes to the Narumi Agency for help in finding the man who gave it to her under the pretense that she wishes to have it removed, but instead she wants to be able to control the invisibility. Isaka agrees, stabilizing the GaiaMemory, only because he knows it will eventually kill her and he will be able to take it from her after she dies, giving him the power of invisibility without the Dopant transformation. However, by killing her and using his EngineBlade as a defribilator to quickly revive her, Kamen Rider Accel removes the Invisible Memory and crushes it.
 * Statistics
 * Identity: Lily Shirogane
 * Gaia Memory: Invisible Memory
 * Actor: Nao Nagasawa (長澤 奈央, Nagasawa Nao?)
 * Memory Break: Kamen Rider Accel's EngineBlade attack
 * Episodes: 27-28

Lily is portrayed by Nao Nagasawa (長澤 奈央, Nagasawa Nao?). She previously portrayed Nanami Nono on Ninpuu Sentai Hurricanger.

Nightmare
Hajime Fukushima (福島 元, Fukushima Hajime?) is a Futo University student who also works as an assistant to Professor Akagi. He is in love with another university student named Himeka Yukimura when she called him her "prince" but learns that she calls evert male that assists her, at the thought of never being loved back he suffered from insomnia. He purchased the Gaia Memory to give Himeka the same amount of pain by never giving her a good night sleep. As the Nightmare Dopant (ナイトメア・ドーパント, Nightmare Dōpanto?) Fukushima has the ability to enter peoples' dreams as well as manipulate them in his favor. He traps his victims in their dreams and uses a massive dreamcatcher-like net to place them in a coma. The victims are branded with a letter H on their forehead, for Hajime and Himeka. He does this to trap his rivals in their worst nightmare. Outside of dreams the Dopant's only known ability is to shoot energy projectiles. However in dreams the Dopant's powers are unaffected by a person's pure conciousness, as demonstrated by Phillip. While Fukushima faked being a victim himself he is found out by Shotaro and defeated by LunaMetal Maximum Drive.
 * Statistics
 * Identity: Hajime Fukushima
 * Gaia Memory: Nightmare Memory
 * Episodes: 29-30
 * Memory Break: Kamen Rider Double LunaMetal's Metal Illusion

Zone
Suzuko Arima (有馬 鈴子, Arima Suzuko?), the wife of Maruo Arima, uses the powers of the Zone Dopant (ゾーン・ドーパント, Zōn Dōpanto?) to teleport anything it sees into a different area, similar to moving the pieces of a shogi board. In the past, Suzuko used these powers to assist her husband in his crime wave. However, she lost the Gaia Memory ten years ago and it was found by Sokichi Narumi, and he then hid it in a bear statue he kept in a vacation cabin. When Shotaro finds it and discovers that it is Suzuko's, she distracts him and takes it from him, enabling her to attack him and help Maruo once more. She is defeated by the Bicker Finallusion Maximum Drive.
 * Statistics
 * Identity: Suzuko Arima
 * Gaia Memory: Zone Memory
 * Episode: 32
 * Memory Break: Kamen Rider Double CycloneJokerXtreme's Bicker Finallusion

Suzuko Arima is portrayed by Ryoko Gi (魏 涼子, Gi Ryōko?).

Yesterday
Yukie Sudo (須藤雪絵, Sudō Yukie?) is the younger sister of Kirihiko Sonozaki, and has come to Futo to take revenge against Saeko Sonozaki for her brother's death. With the powers of the Yesterday Dopant (イエスタデイ・ドーパント, Iesutadei Dōpanto?), she is able to force anyone to relive the actions of the previous day. Unlike most Dopants, she retains all of her intellect and is not driven insane by the Memory, making her able to execute extremely complex manipulations through skillful use of Yesterday. After attacking landsharks who threatened to take down her old elementary school, she sets up Shotaro as a makeshift assassin to kill off Saeko by going under the alias Yuko Fuwa and asking Shotaro to supposedly help find a missing cat named Kinou (literally meaning 'yesterday') until Accel gets in the way and her control over Double is eliminated. Her real plans however were to get close to the Museum to get a better chance of exacting revenge by putting Saeko in a 'yesterday trance.' But this plan backfires after the altering done by Isaka to Saeko's Taboo Dopant form to have Yukie be put into the trance instead. When Double uses Prism Break the trance is broken and when she regains conscious after the Memory Break she remembers about the time she shared with her brother while also gaining amnesia as a side effect of the Yesterday Memory.
 * Statistics
 * Identity: Yukie Sudo
 * Episodes: 33-34
 * Memory Break: Kamen Rider Double CycloneJokerXtreme's Prism Break

Yukie Sudo is portrayed by Kaoru Hirata (平田 薫, Hirata Kaoru?).<sup class="reference" id="cite_ref-18">[19] She previously portrayed Yuka Yamazaki in Mahou Sentai Magiranger.

Quetzalcoatlus
Nagisa Shimamoto (島本 凪, Shimamoto Nagisa?) is a worker at the Futo Aviary who becomes the unwilling subject of Isaka's experimentation with the powers of the Quetzalcoatlus Dopant (ケツァルコアトルス・ドーパント, Ketsarukoatorusu Dōpanto?). The fear she has of Isaka causes the Living Connector to mutate, making the Quetzalcoatlus Memory stronger (the Gaia Memory appears to have its own set of wings) for Isaka to use for his own purposes. Isaka makes a copy of the Quetzalcoatlus Memory and uses it on a Red-and-green Macaw to threaten Shotaro with a sample of the Memory's powers as the giant Quetzalcoatlus Dopant drags Nagi off until Kamen Rider Double saves her. This incarnation of the Dopant is defeated by CycloneJoker Xtreme's Bicker Charge Break Maximum Drive, but the Quetzalcoatlus Memory still exists for Isaka to use on himself later. After the Weather Dopant is defeated by Kamen Rider Accel Trial, the Quetzalcoatlus Memory is ejected from Isaka's body and it is destroyed by Accel Trial.
 * Statistics
 * Identity: Nagisa Shimamoto; Unnamed Macaw (Copy); Shinkuro Isaka (absorbed power)
 * Episodes: 35-36
 * Memory Break: Kamen Rider Double CycloneJokerXtreme's Bicker Charge Break (Copy); crushed by Kamen Rider Accel Trial (Real)

Nagisa Shimamoto is portrayed by Miyuu Wagawa (和川 未優, Wagawa Miyū?).

Hopper
The mysterious "Grasshopper Woman" (イナゴの女, Inago no Onna?) is a hitwoman who works for the Museum as one of its top two eliminators along with the Smilodon Dopant, originally a normal girl until her mind was rewritten by neuroscientist Satoshi Yamashiro who was kidnapped to serve as a Museum researcher. She has purple hair, is dressed in Gothic Lolita attire, and carries a heart-shaped box full of boiled grasshoppers (いなごの佃煮, inago no tsukudani?) that she eats and offers to others, often before attacking with her kicking fighting style and electroshock boots if they turn her down. As the Hopper Dopant (ホッパー・ドーパント, Hoppā Dōpanto?), she is able to jump and kick with great intensity, similar to the original Kamen Riders. She is called upon by Ryubee to murder Yamashiro when he escapes from the Museum. After mortally wounding Yamashiro, the Hopper Memory is destroyed through Kamen Rider Accel Trial's Machine Gun Spike Maximum Drive. Before Ryu can arrest her, the girl attempts to escape when the Smilodon Dopant kills her so she can not reveal any sensitive information concerning the Museum.
 * Identity: Unnamed
 * Episodes: 37-38
 * Actor: Minami Tsukui
 * Memory Break: Kamen Rider Accel Trial's Machine Gun Spike

Gene
Toru Kawai (川相 透, Kawai Tōru?) is an independent film director who uses his powers as the Gene Dopant (ジーン・ドーパント, Jīn Dōpanto?), who uses the DNA Mixer (ＤＮＡミキサー, DNA Mikisā?) on his right arm to change the genetic structure of whatever it touches, to make his magnum opus on his own and then force theater goers to sit through the 7-hour uncompleted film. When he traps Shotaro and Akiko, they soon discover him and easily defeat him, as the Gene Dopant is not a powerful fighter. To rehabilitate him, Akiko takes control of the movie's production, while trying to hook him up with its star Ai Nijimura who he impersonated beforehand, but this only upsets Toru. It is revealed that Ryubee had specifically chosen Toru for his high compatibility with the Gene Memory so Wakana could use him to activate the Gaia Progressor and evolve into ClayDoll Xtreme. After helping with this process and seeing the end results, Toru gives up the Gene Memory which is destroyed by Kamen Rider Double CycloneJoker Xtreme, and he begins working on the movie in his own way with Ai.
 * Identity: Toru Kawai
 * Episodes: 39-40
 * Actor: Naoki Kawano
 * Memory Break: Crushed by Cyclone Joker Xtreme

Toru Kawai is portrayed by Naoki Kawano (川野 直輝, Kawano Naoki?). He previously portrayed Long in Juken Sentai Gekiranger.

Old
Takashi Aiba (相馬 卓, Aiba Takashi?) is a fortune teller in Futo who reads people's palms, but is secretly known as the Ager (ふけさせや, Fukesaseya?). With enough payment, he uses his powers as the Old Dopant (オールド・ドーパント, Ōrudo Dōpanto?) to make people older through his use of the Old Creak (オールドクリーク, Ōrudo Kurīku?). The attack is released from the Old Creak in a manner similar to that of the Terror Dopant. The Old Dopant also has two sides to his body: one that uses the Old Creak, and another that attacks with physical force. Although Shroud states that only the power of Kamen Rider Double CycloneAccel Xtreme can defeat the Old Dopant due to Philip and Ryu's immunity to its attacks, Double CycloneJoker Xtreme and Accel Trial are able to defeat the Old Dopant using a combination of their attacks.
 * Identity: Takashi Aiba
 * Episodes: 43-44
 * Memory Break: Kamen Rider Accel Trial's Machine Gun Slash
 * Actor: Masakazu Azuhata

Energy
A nameless pet shop employee (ペットショップの店員, petto shoppu no tenin?) is the leader of the EXE (エグゼ, Eguze?) group who uses a Gaia Memory that is strong enough to resist the powers of Shotaro Hidari as Kamen Rider Joker. As the Energy Dopant (エナジー・ドーパント, Enajī Dōpanto?), he is able to fire blasts of electromagnetic energy as well as use his left arm like a rail gun. He is defeated when Philip returns and joins with Shotaro to become Kamen Rider Double CycloneJoker once more, destroying the Energy Memory through the Joker Extreme Maximum Drive.
 * Identity: nameless pet shop employee
 * Episode: 49
 * Memory Break: Kamen Rider Double's Joker Extreme
 * Actor: Tomu Suetaka

Movie Dopants
In Kamen Rider × Kamen Rider Double & Decade: Movie War 2010's Kamen Rider Double: Begins Night, Masquerade Dopants appear in the movie as well.

Death Dopant
The Death Dopant (デス・ドーパント, Desu Dōpanto?), has the ability to bring anyone back from the dead and carries a scythe with a white dummy attached to it. It was defeated by Kamen Rider Skull at an unknown time. It's appearance was used by the Dummy Dopant in a plot he devised.
 * Statistics
 * Gaia Memory: Death Memory
 * Memory Break: Kamen Rider Skull's Skull Banisher

Dummy Dopant

 * Identity: Father Robert Shijima
 * Actor: Toru Tezuka (手塚 とおる, Tezuka Tōru?)

Father Robert Shijima (神父・ロベルト志島, Shinpu Roberuto Shijima?) is a figure within the cult known as the Order of Silence and Darkness. Shijima can become the Dummy Dopant (ダミー・ドーパント, Damī Dōpanto?) who can assume any form he wishes. Among these forms are Sokichi Narumi and the Death Dopant. Using the Death Dopant's form, Shijima plays with the heads of high class people by assuming the forms of those recently deceased to con them into an early grave and assume their identities. One such con involves him assuming the form of Erika Mutsuki, Asami's sister. But once exposed, the Dummy Dopant evades Double as he finds himself in the the middle of Decade's fight with Super Shocker, where he takes control of the Mammoth Mecha (マンモスメカ, Manmosu Meka?). However, the Dummy Dopant meets his end when he is assimilated by the Neo Organism as it becomes the inhuman Ultimate D. In materials to promote the film, the Dummy Dopant was referred to as the "mysterious Dopant" (なぞのドーパント, nazo no Dōpanto?).

Dr. Shinigami Dopant
At some unknown point, Eijiro Hikari was given the Dr. Shinigami Memory by Ryubee Sonozaki, which causes him to transform into Super Dr. Shinigami when conned by Narutaki into speaking the word "Ikadevil". In this form he acts as the leader of Super Shocker. After the Neo Organism takes over the Super Crisis Fortress, Super Dr. Shinigami is trapped within the fortress until it is hit by Kamen Rider Double HeatMetal's Maximum Drive, which destroys the fortress and the Dr. Shinigami Memory. This causes Eijiro to forget the entire experience. How and when Eijiro originally encountered Ryubee or was injected with the Memory is entirely unclear.
 * Identity: Eijiro Hikari
 * Actor: Renji Ishibari

Other T2 Dopants
In addition to the above five Dopants, there are also new IceAge, Nasca, Violence, and Weather Dopants who transform using T2 Gaia Memories. In addition to the above, Eternal, and Joker, the other Gaia Memories featured in the movie are Accel, Bird, Dummy, Fang, Gene, Key (キー, Kī?), Ocean (オーシャン, Ōshan?), Puppeteer, Queen (クイーン, Kuīn?), Rocket (ロケット, Roketto?), Skull, Unicorn (ユニコーン, Yunikōn?), Xtreme, Yesterday, and Zone.

Oyakodon

 * Identity: Izo Aida
 * Memory Break: Kamen Rider Double CycloneJoker Xtreme's Bicker Charge Break

In the Hyper Battle DVD, Izo Aida (相田 伊三, Aida Izō?), the master of the OmuriFu Shop, transforms into a Dopant initially known as the "Donburi Dopant" (丼・ドーパント, Donburi Dōpanto?) and attacks rival yatai stands to become the number one restaurant in Futo for his daughter's dream. The Dopant can move at extremely fast speeds, release projectiles from its mouth, and is armed with a pair of giant chopsticks. The Dopant's strength is due to balacing the fluffiness and juicyness of the Donburi dish it holds. Philip discovers that the Dopant can only be defeated upon discovering what type of donburi dish he holds, so the Narumi Detective Agency holds a contest to discover the contents. When Shotaro's chicken and hard-boiled egg "Hard-Boiledon" gives Philip a hint, he identifies that the Dopant is the Oyakodon Dopant (オヤコドン・ドーパント, Oyakodon Dōpanto?); the Gaia Memory he uses has the combined powers of both the Egg Memory (エッグメモリ, Eggu Memori?) and the Chicken Memory (チキンメモリ, Chikin Memori?). When Aida transforms into the Donburi Dopant, the words "Fuwafuwa" (ふわふわ?, Fluffy) and "Juicy" (ジューシー, Jyūshī?) appear, similar to the transformation sequence of Double.
 * Appears in: Donburi's α/Farewell Recipe of Love
 * Actor: Hiroshi

The design of the Oyakodon Dopant is based on the winning entry of a Dopant drawing contest for Televi-Kun magazine and the Gaia Memory is based on the Televikun CycloneJoker Memory that came with the July 2010 issue of Televi-kun.

Bean
In the webisode "The Doctor is Happy About B/Now, In the Mumbling", the Bean Memory is tested on Makura with the intent to turn him into the Bean Dopant (ビーン・ドーパント, Bīn Dōpanto?). This Gaia Memory had previously appeared in the television series in where it is shown being forcibly used on a Museum test subject before resulting in the man's death.

Kabuki
In the webisode "The K is Drowsy/A Speaking Only Experiment", the Kabuki Memory is tested on Jinno with the intent to turn him into the Kabuki Dopant (カブキ・ドーパント, Kabuki Dōpanto?).

Yoga
In the webisode "The Comedy of Y/The Man Searching for Curry", the Yoga Memory is tested on Makura with the intent to turn him into the Yoga Dopant (ヨーガ・ドーパント, Yōga Dōpanto?), a Dopant with stretching powers not unlike the Luna Dopant.

UFO
In the webisode "The U is a Mystery!/Rondo", Master of the Fumen ramen stand becomes the UFO Dopant (UFO・ドーパント, Yūfō Dōpanto?) while Jinno and Makura were studying the UFO Memory.