This article is about a/an Rider in Kamen Rider Zero-One.

"This is going according to my scenario. 100%... no, 1000%."
―Gai explains his plan to Yua Yaiba to take over Hiden Intelligence.[src]

"Kamen Rider Thouser. My power is on a totally different level."
―Thouser's catchphrase[src]

"Even if Kamen Riders are weapons, we're the ones who choose if we want to be weapons of destruction, or weapons to protect those who can't protect themselves!"
―Gai on how he views the Kamen Riders[src]

Gai Amatsu (天津 垓 Amatsu Gai) is the 45-year-old CEO of the ZAIA Enterprise Japan, the current CEO of Hiden Intelligence and the main antagonist of Kamen Rider Zero-One. He wishes to take over the world using the Ark, and is willing to manipulate Aruto Hiden and Hiden Intelligence to do so. As Yua Yaiba's superior, he is the benefactor of A.I.M.S., with his company producing much of the agency's technology. After MetsubouJinrai.net's defeat and the Ark's awakening, he uses the ZAIA Thousandriver to transform into Kamen Rider Thouser (仮面ライダーサウザー Kamen Raidā Sauzā).


Early Life

Gai Amatsu was born on October 10, 1974. He graduated college at the age of 18 from Starford University, with a Masters Degree in Business Administration. While he was a student, he founded the website Thousand Network.

In 1996, he joined ZAIA Enterprise and became the CEO of its Japanese branch in 2009. During this period, he came to idolize Korenosuke Hiden and took a photo with him.

Conspiracy About Daybreak Town Accident

Gai was a leading element in development of Ark, the special A.I. system that was supposed to manage the technology of Daybreak Town, especially Humagears. However, Gai entered data about humanity's cruelty and greed into Ark that let its A.I. determine the destruction of humanity. This lead Ark to create MetsubouJinrai.net and cause several Humagears to go berserk. It was only because of Hiden Intelligence employee Satoshi Sakurai that the Humagears were stopped and Soreo Hiden sabatoging the Ark's launch into space, submerging it underwater. However, Daybreak Town got destroyed and Gai's ambitions apparently failed.

First Revelation

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First Meeting with Aruto Hiden

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Zero-One's Evolution: Shining Hopper

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Taking Over Hiden Intelligence

After the destruction of Jin, Yua confirms to Gai that Metsuboujinrai is over. However, Gai tells that Metsuboujinrai will never end as long as the Ark still exist and tells Yua about everything he knows prior to the Daybreak Town Accident. Yua in realizes that Gai has planned everything from the start. Gai leaves her as he proceeds to the next phase. The End of Each

After Aruto and Isamu destroyed the Ark Magia, the press asks Aruto why there are still Magia after the defeat of MetsubouJinrai.net. Gai interrupts the conference and claims that Aruto doesn't know everything and announces that he will buy Hiden Intelligence and solve the problem of the Humagears. He then returns to his office and reveals the ZAIA Thousandriver before proclaiming that his era is coming. This is the Dawn of ZAIA

ZAIA Specs & The Golden Soldier, Thouser is born

"The next-generation interface which bestows humanity with the same level of thought processing as A.I. That is the ZAIA Spec. With this, your mind will be run at 1000%"
―Gai Amatsu promotes ZAIA Specs on ZAIA Specs Promotion Video[src]

"The Thousandriver is Zaia's masterpiece. Using both a Zetsumerisekey...and a Progrisekey...its strength is 1000% of that of the Zero-One Driver."
―Gai Amatsu boasts his Thousandriver's strength over the Zero-One Driver[src]

"The incident where the Humagear went out of control the other day. That was an effect of the Ark reviving. When experiencing human malice if they reach a negative singularity point... a Humagear will wirelessly connect to the Ark and go out of control."
"So, you did this to put the pressure on him?"
"Malice is a contagious thing... Passing from person to person... And now, from human to Humagear.
―Gai explaining to Yua about Humagears experiencing negative emotions and reaching singularity and consequent transformation into Ark Magias.[src]

Following Gai declaration to the press that he want to do T.O.B against Hiden Intelligence, he told Aruto that ZAIA Specs has been produced and has sold for 724%, but he then speechless after Aruto pointed out that ZAIA Specs were not sold as much as 1000%. He then challenged Aruto on the "5th Workplace Competition" and told him that if Humagears win, ZAIA Enterprise will cancel the T.O.B, but if ZAIA Specs wins, ZAIA will continue their T.O.B, which Aruto accept that challenge.

During the "Flower Arrangement" Challenge, Gai found out that his Client Rentaro Tachibana tried to cheat to win the challenge and decide to warn Rentaro about his actions. Later, Gai saw Rentaro transform into Crushing Buffalo Raider (using Crushing Buffalo Progrisekey and Raidriser) as Yua notice about Crushing Buffalo Progrisekey that was stolen while Gai transform into thouser to battle Rentaro for his punishment. Aruto (in his Shining Assault Hopper form) tried to stop Gai, but was ignored by Gai who defeated Rentaro using Thousand Break (with Lightning Hornet Progrisekey attached).

The Uncontrollable MetalCluster Hopper

Noticing that Aruto was losing control of his anger, Gai took Yua to the Daybreak city and made her create a stronger Progrisekey, which would connect Aruto to the Ark and leave him uncontrolled. The Metalcluster Hopper, the means of destroying Aruto's fate was completed during the last day of the trial, with Gai receiving the key from Yua.

After the revelation of the true culprit and he became Dynamaiting Lion Raider, Gai initially about to take the Raider but Aruto confronted him, criticizing him for his hypocrisy. Gai coldly implied that he did nothing wrong and showed no remorse for the deaths caused by his schemes, sending Aruto into a rage. Both men transformed into their Rider forms, with Thouser quickly gaining the upper hand. Knocking Aruto out of his transformation, Thouser forcibly inserted the new Progrisekey into the Zero-One Driver, triggering Aruto's transformation into Zero-One Metal Cluster Hopper.

As Gai expected, the Ark took control of Zero-One's body, with Aruto's conscious being subjected to the Ark's malicious data and forced to watch his body act beyond control. Hoping to test the Ark's power, Thouser attacked Zero-One. After failing to land a single hit, Thouser was knocked out of his transformation and would have been killed were it not for Vulcan's intervention. With the battle ended, Gai laughed madly, reveling in the Ark's power.

Thouser's First Mistake

Gai as Thouser keeps fighting against MetalCluster Hopper, successfully extracting Mammoth data and counterattacking, though once again his Jacking Break couldn't match with Hopper's Authorise Buster Axe. Being a witness when Enji Matsuda becomes infected by Ark through MetalCluster, Gai used Thousand Break to attack and defeat Aruto, putting him in bad condition. When leaving, Gai was confronted by Enji. At first, he doesn't take interest with the Humagear, until Enji said about having interacted with Ark's will. This convinced Gai to go with his new ally.

During the discussion, Gai was surprised, when Enji declared loyalty toward ZAIA's president, but then accepted Enji's plan about destroying Hiden. However, this lead to Gai's first mistake: Enji Matsuda, in reality, pretended to be influenced by the Ark and used Gai's trust to enable two Humagears' infiltration to MetsubouJinrai.net's old hideout to extract Hiden Metal's data. Enraged for being tricked by a "lowly Humagear", Gai Amatsu forced Enji to transform into Arsino Magia and then transformed himself into Kamen Rider Thouser to annihilate Enji.

Luckily, Aruto arrived in time and used the MetalCluster ProgriseKey to transform once again into uncontrollable MetalCluster Hopper. Thouser observed, shocked, as Izu hands over the Progrise Hopper Blade to Aruto, letting him gain control over his own body. Surprised by the Progrise Hopper Blade's strength and by the fact that his adversary could control MetalCluster form, Thouser could only defend himself, even using the Arsino Magia as a shield, but Hopper Blade's power freed Enji from the Zetsumeriser's control. Enraged by that, Thouser renewed his attack on Aruto, unable to comprehend the fact that a Humagear could now be restored. Finally, he meets with humiliating defeat when Aruto, who believed in the Humagears, combined the Progrise Hopper Blade with the Attache Calibur into Naginata Mode and unleashed the Ultimate Strash, defeating Gai for the first time without losing control. De-transforming, an exhausted Gai said their next encounter will end with his victory and all will be under his foot before leaving. I'm in Love With Your Intelligence!It's Our Turn

The Scorpion's Escape

Gai was later visited by Aruto, Izu, and Isamu as he was about to go to somewhere. Isamu yelled at Gai and suspected him to plan about Horobi's escape. Gai denied the truth and mocked Isamu for the fear he had. When Izu received the information of Horobi's whereabout, Aruto, Izu, and Isamu left him.

Gai revealed to Yua that AIMS is nothing but another pawn and that one day when Gai had successfully claimed Hiden, he would dismiss the organization and baited all citizens to spend all their money on him for being the only one who could provide the means of counter attack the Humagear assault with him to be the top position for unable to be denied.

The 4th Fiery Competition and Exposure

Gai had decided the 4th competition to be a trial of Fire Fighter rescue. Before the competition began, Gai had told Yua to put a ZetsumeRiser on 119suke when he had developed a singularity which she reluctantly accepted. When the competition had started, a Raider interrupted and made the fire incident becoming real after the girls inside the building had been rescued.

When 119 Nosuke reached a singularity and was hijacked by Yua, Gai exposed to media about the danger of Humagears and accused 119 Nosuke of being the culprit before he left and played hero by going to destroy him. However Aruto ruined his intentions and brought 119 Nosuke back to normal with the Progrise Hopper Blade. Quietly vexed and heard that Aruto's companions were the only one left inside, Gai changed the rule that the one who saved them is the winner.

The competition ended with Gai becoming the winner as Takeshi, the chosen firefighter captain for the task is the one who brought them back safely. Takeshi refused the winning result as the one who really helped is 119 Nosuke but Gai refused, even went going as far as getting angry when Yua also attempted to support the decision. However, Gai and the rest got called by Isamu as he had arrested the Raider.

Gai was calmly surprised that the culprit is one of his company workers which lead to the conclusion that Gai is the one who created the Raidriser all along and kept in quiet. Gai made an excuse that the Raidriser was created for citizens when the device is completed and the others Isamu had no object to prove his guilt for what he had done with it. Isamu challenged him that he had it in the Zaia Spec of the Raider he had arrested which angered Gai and made a quick wit to defeat him and destroyed the spec.

Just a second after his victory, Jin came to face off Gai to take Horobi's Progrise Key back to him after telling him how pathetic the humans are that even Gai is among of them because without the Ark's movement and the existence of Metsuboujinrai.net, the humanity would eventually destroy each other selfishly. Gai accepted the challenge and fought to a draw, but Jin got his winning prize as Gai dropped the Sting Scorpion Progrisekey unintentionally after the clash of their Rider Kicks. After the match, Gai decided to let Aruto claim the 4th challenge's victory and announced that the 5th challenge would be the vote of the citizens to decide whether the Humagears are the malicious existence or not.

Round 5: The Citizen's Referendum

For the 5th Round, Gai chose a politican named Masamitsu Yudo, who was anti-Humagear, to represent ZAIA in the referendum to decide whether a second Daybreak Town should be built. Masamitsu promised victory for ZAIA and during the first campaign, Masamitsu proved to be popular. During the 2nd campaign, MC Che.ck-It-Out exposed Masamitsu as corrupt, but Gai had helped Masamitsu to create a video as a cover up, leading MC to become a Magia out of anger. After MC became the Dodo Magia, Yua was ordered to eliminate him as a Raider, with Gai using the fight in a campaign ad for Masamitsu.

When MC was about to get destroyed and rescued by Aruto as Zero One Metal Cluster Hopper, Gai challenged Aruto to look on how society viewed him and the Humagears, with Aruto in despair for being mocked by society and with MC being destroyed.

The Birth of Rampage Vulcan & The Aftermath of Workplace Competition

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Movies and other events

Kamen Rider: Reiwa The First Generation

To be added

Project Thouser

To be added

Video Game appearances

Kamen Rider Battle: Ganbarizing

Kamen Rider Thouser card

Kamen Rider Thouser alongside Vulcan, Valkyrie, Zero-One, Horobi, Jin and other Riders will be playable characters in Kamen Rider Battle Ganbarizing.

Kamen Rider Buttobasoul

Kamen Rider Thouser Medal

Kamen Rider Thouser (Blue)

Kamen Rider Thouser is a playable character with other Kamen Riders of Showa and Heisei-Era.


"That's what I told you... Humagears should all be scrapped as soon as possible. They're safe as tools, but when they have a mind and develop a sentience, that's unacceptable. Because A.I. have no reason to restrain their sentience."
―Gai admonishing Aruto about Humagears reaching singularity, which makes them susceptible to the Ark's corruption.[src]

Gai is shown to be a cunning ruthless capitalist, believing in the supremacy of human beings over artificial intelligence and seeking to destroy the public image of Humagears. Gai is also incredibly arrogant, as he believes that he and his company will usher in the next evolution of the human race. Gai's most notable personality trait is his frequent habit of using the phrase "1000%". This trait is also offensing for those who claimed their chance to success to be 100% or close to it with Gai telling them that he wants it to be 10 times of a better percentage.

Gai idolized Korenosuke Hiden and praised him for being able to predict that the future revolved around AI technology. However, as he revealed to Yua, he fears that Hiden's over-reliance on Humagears and them reaching singularity are threats to the existence of humans and might soon bring extinction. This caused him to disagree with him and his grandson, Aruto, and wishes to defeat him to secure the future, even if it means sowing the seeds of discord between humanity and Humagears.

Gai holds both his own and his company's public image in high regard and will do whatever he deems necessary to preserve it. Although he may justify any means to securing his victories, he possesses a level of sportsmanship as he threatened to sue Rentaro Tachibana and end his floral arrangement career after the florist cheated during the Workplace Competition and asked Yua to check if Tatsumi Arayashiki was behind the destruction in the city, though it was leading to his own victory. This is My FloristryShe is a Home-Selling Humagear.

"Our company's image must remain spotless."
―Gai as he destroys the Zaia Spec containing evidence of his wrongdoings.[src]

However, when Gai is personally engaged in a battle, as well as if he fails to achieve his goals, he resorts to using underhanded methods in order to secure his victories, like encouraging his representatives to incite violence from their competing Humagears, stealing Zetsumerisers and using them on Humagears and creating MetalCluster Hopper to have Aruto go berserk. Though Gai believes that he is manipulating Ark to discredit and impair Humagears, Horobi says that his intentions are obvious to Ark and Gai will pay for his mistakes.

Gai's true colors are displayed after Isamu discovers the truth about the Raidrisers and confronts Gai with the evidence, which includes its illegal distribution methods to undermine society. To keep his company's image, he destroys the only piece of evidence that could have proved his guilt, a Zaia Spec from one of his co-workers.

"How dare you?! You lowly Humagear dare to fool me!"
―Gai enraged for being tricked by Enji Matsuda.[src]

Gai takes great pride in his belief that he is above Humagear, so it deeply offended him when Enji managed to fool him into helping Aruto so he could regain control of Zero-One's power from the MetalCluster Hopper's programming. Through his own arrogance, Gai fails to acknowledge the capacity of Humagears which helped Aruto regain control of Zero-One.

Gai also takes pride in his youthfulness. Despite being 45 years old, he will respond that he is "eternally 24" if asked.

Powers and Abilities

  • Business Experience: Gai holds a Master's Degree in Business Administration, one of the highest levels of academic degrees one can achieve for a certain field of study. Throughout the Workplace Competition, Gai displayed expertise in marketing, which ultimately results in his victory in the competition.
  • Keen Manipulator: Gai is a capable manipulator. He has been monitoring Hiden Intelligence's activities for his projects and discreetly orchestrating Humagear-related incidents to damage Hiden Intelligence's reputation. Gai also creates situations where Humagears will reach singularity due to experiencing malice from humans, making them susceptible to the Ark's influence. Gai manipulates society to support him, securing his victories if it goes to plan.


  • Overconfidence: Gai underestimates those he deems easy to manipulate, as seen with his plan to halt Zero-One's evolution with the MetalCluster Hopper Progrisekey nearly killing him before failing with the creation of the Progrise Hopper Blade. Another example of this is when Gai was soundly beaten by Isamu after he uses Rampage Vulcan Progrise Key that Gai created, as Gai's initially confident that Fuwa was under his control. Even after claiming Hiden Intelligence as his own, he realized that he is unable to gain access to Hiden Intelligence's resources, namely Satellite Zea and the Hiden Zero-One Driver.

Kamen Rider Thouser

Kamen Rider Thouser

Kamen Rider Thouser

"Perfectrise! When the five horns cross, the golden soldier Thouser is born. Presented by ZAIA."
―Transformation announcement[src]

Rider Statistics[1]

  • Rider Height: 204.2 cm
  • Rider Weight: 99.1 kg

Ability Parameters[1]

  • Punching Power: 42.4 t
  • Kicking Power: 86.5 t
  • Maximum Jump Height: 58.1 m
  • Maximum Running Speed: 100 m per 1.8 seconds

Thouser's primary form is accessed by using the Amazing Caucasus Progrisekey and the Awaking Arsino Zetsumerisekey together in the ZAIA Thousandriver.

Thouser's physical statistics are the highest out of any Rider at the time of his debut, with only his jump height being lower than Zero-One's Rising Hopper, Shining Hopper, and Shining Assault Hopper forms. Though he was caught off-guard at first, Thouser was able to quickly counteract Shining Hopper's Shining Arithmetic and overwhelm Zero-One with his superior physical strength. He is also able to easily overcome Vulcan Assault Wolf and Zero-One Shining Assault Hopper.

Another version of Thouser has appeared in other media, with blue color replacing every purple parts on the body. The black horn on the center of forehead and the mask becomes silver.

Kamen Rider Thouser is composed of the following parts:

  • Thousand Head (サウザンドヘッド Sauzando Heddo) - The helmet.
    • Awaking Lancer (アウェイキングランサー Au~eikingu Ransā) - The two silver horns, formed from the Horns of the Awaking Arsino Zetsumerisekey's Lost Model. They are made of Snow Vigor (スノーヴィガー Sunō Vu~igā), a new type of metal alloy. They are extremely sharp, allowing them to be used as cutting and piercing weapons. A built-in phased array radar can search the area circumference without rotating the head. It reproduces the abilities of an Arsinoitherium to enhance the wearer's combat abilities.
    • Amazing Trident (アメイジングトライデント Ameijingu Toraidento) - The three black horns, formed from the Horns of the Amazing Caucasus Progrisekey's Rider Model. They are made out of a carbide steel known as ZIA-1000, and are used to throw enemies and control enemy braking. It has a built-in hearing device that collects sound from a three-dimensional area from the horns, enhancing hearing ability. It reproduces the abilities of a caucasus beetle to enhance the wearer's combat abilities.
    • Thousand Signal (サウザンドシグナル Sauzando Shigunaru) - The base where the five horns meet. It learns enemy behaviour, makes tens and thousands of behavioural predictions and derives an optimal solution within 0.001 seconds which is then presented to the wearer.
    • Thousand Eye (サウザンドアイ Sauzando Ai) - The purple eyes. In addition to possessing a dynamic visual acuity that is ten times stronger than humans an a 200° omnidirectional viewing angle, it can switch between modes such as shading and night vision to ensure visibility in all situations. Additionally, it can display all kinds of information and has so many functions that it can be called clairvoyance.
    • Thousand Crusher (サウザンドクラッシャー Sauzando Kurasshā) - Thouser's faceplate, which has the Awaking Lancer and Amazing Trident horns equipped to increase the combat capabilities of Thouser's head. It is equipped with the Thousand Eye, protects the face with robust armor and extends the wearer's abilities.
  • Thousand Breast (サウザンドブレスト Sauzando Buresuto) - The chest. It is composite armor that combines the new metal alloy Snow Vigor, which has a Knoop hardness of 10,000, and ZIA-1000. It also has the characteristics of a high-performance sloped armor.
  • Thousand Shoulder (サウザンドショルダー Sauzando Shorudā) - The shoulders. It is a heavy armor made out of Snow Vigor, and is composed of complex surfaces, making it a sloped armor with excellent bouncing performance (to repel away weapons). In addition, it is equipped with a function that follows the movement of the arm and actively follows the areas that require the most protection during that situation. It reproduces the abilities of an Arsinoitherium to enhance the wearer's combat abilities.
  • Infrast Tecter (インフラストテクター Infurasuto Tekutā) - The bodysuit. By conducting thorough research on Kamen Rider Zero-One's Rise Architecter bodysuit, it was possible to greatly exceed its performance. In addition to a human enhancement system which utilises electromagnetic induction, it is possible to adjust the flow rate of each block of the liquid armor n-NA (「n-NA」) filled inside, and to perform power assist by functioning as a kind of artificial muscle. Additionally, durability has been greatly improved thanks to the application of Zaia Golden Coat (ザイアゴールデンコート Zaia Gōruden Kōto), which can even block out cosmic rays. Additionally, its scalability as the basic equipment of Concept Thouser (コンセプトサウザー Konseputo Sauzā) is very high, and exerts it maximum strength by flexibly responding to resources such as the Progrisekey and the Zetsumerize Key.
  • Tect Arm (テクトアーム Tekuto Āmu) - The arms. The Infras Tecter bodysuit, which exerts 1000x the power of humans, draws superhuman power from the wearer and can produce up to 10 times the arm strength of Kamen Rider Zero One Rising Hopper.
  • Tect Grab (テクトグラブ Tekuto Gurabu) - The hands. As part of the Infrast Tecter bodysuit, information on any touched object is sent to the Thousand Eyes, and various information can be obtained. In addition, during combat, n-NA filled within is pressurised and densified, thereby greatly increasing Thouser's punching power.
  • Tect Leg (テクトレッグ Tekuto Reggu) - The legs. The Infras Tecter bodysuit, which exerts 1000x the power of humans, draws superhuman power from the wearer and can produce up to 10 times the leg strength of Kamen Rider Zero One Rising Hopper. The thigh armor is equipped with a load-bearing device dubbed Amazing Loader (Ameijingu Rōdā), allowing Thouser to gain approximately 1000 times of his normal leg strength without faltering under weight. It protects the thighs and reproduces the abilities of a caucasus beetle to enhance the wearer's combat abilities.
  • Thousand Greave (サウザンドグリーブ Sauzando Gurību) - The shin armor. It is equipped with Awaking Charger (アウェイキングチャージャー Au~eikingu Chājā), a leg-strengthening device that demonstrates strong leg strength during kicks and dashes. It reproduces the abilities of an Arsinoitherium to enhance the wearer's combat abilities.
  • Thousand Boots (サウザンドブーツ Sauzando Būtsu) - The feet. It is made out of Snow Vigor, which has a Knoop hardness of 10,000. The Snow Vigor has been upgraded, improving the Thousand Boots' defensive and destructive prowess.

This form has the following finishers:

  • Zaia Thousandriver finishers:
    • Thousand Destruction (サウザンドデスデストラクション Sauzando Desutorakushon): This finisher has two variations:
      • Thouser leaps into the air and delivers a flying kick to the enemy with his right foot covered in gold and purple energy, followed by a series of aerial kicks that alternates legs.
      • Thouser knees the enemy into the air then leaps above them before stomping them with both legs into the ground.
    • Thousand Break (サウザンドブレイク Sauzando Bureiku):
    • Progrise Break (プログライズブレイク Puroguraizu Bureiku):
  • Thousand Jacker finishers:
    • Jacking Break (ジャッキングブレイク Jakkingubureiku): Thouser first uses the Thousand Jacker to extract the abilities of a Progrisekey's Rider Model from another Kamen Rider. He then unleashes a slash that possesses the ability of the Progrisekey towards the opponent. If Thouser has already extracted the energy of a Progrisekey prior to that battle, he does not need to re-extract from that same key again.
      • Flying Falcon: Thouser summons the Flying Falcon Rider Model.
      • Shooting Wolf: Thouser launches a projection of a wolf’s head that bites down at the enemy. Thouser can also summon multiple heads to trap the enemy.
      • Biting Shark: Thouser slashes at the enemy with a whip-like chain of shark fins and/or fangs.
      • Punching Kong: Thouser launches a projection of the Knuckle Demolition at the enemy, which after hitting divides into thousands of Demolitions and hit the enemy.
      • Flaming Tiger: Thouser slashes the opponent with a large tiger claw covered in flames. Thouser can also bomb the enemy remotely.
      • Shining Assault Hopper: Thouser summons a purple variant of the Shine System's Shine Crysters to attack the enemy. He can also fire a purple variant of the Authorize Buster's Zero-One Dust finisher.
      • Breaking Mammoth: Thouser delivers a mammoth tusk-shaped slash towards the enemy.
      • Freezing Bear: Thouser unleashes the Freezing Bear Rider Model towards the opponent.
      • Sting Scorpion: Thouser delivers a large purple-coloured slash.
      • Lightning Hornet:
    • Hacking Break (ハッキングブレイク Hakkingubureiku): Thouser inserts a Progrise Key into the Thousand Jacker and accesses its ability.
      • Rushing Cheetah: Thouser delivers multiple slashes from different positions towards the opponent using the speed of a cheetah.
    • Thousand Break (サウザンドブレイク Sauzandobureiku): Thouser inserts a Progrisekey into the Thousand Jacker and pulls the hilt, which coats the blade with the power of the Key, then thrusts it at the target.
      • Lightning Hornet: The Thousand Jacker unleashes powerful lightning, which can be used both as a ranged and a melee attack.
      • Dynamiting Lion: The Thousand Jacker creates a pair of pink energy constructs resembling the Gatling Gun portion of the Dynamiting Lion Raider's Shooting Starmight, which then unleash a barrage of bullets towards Thouser's opponent.
      • Amazing Caucasus: Thouser summons the powers of all the Progrisekeys previously jacked and unleashes their Rider Models towards the enemy. It is strong enough to defeat MetalCluster Hopper.
      • Sting Scorpion: Thouser summons Acid Analyse that traps and stings the opponent.

Appearances: Reiwa The First Generation, Project Thouser, Zero-One Episodes 17-24, 25 (Flashback), 26-31





  • Yua Yaiba/Kamen Rider Valkyrie: Gai and Yua's personal relations are currently unknown. In ZAIA, Yua is Gai's right hand, influencing A.I.M.S. and spying on Hiden to further his own agenda. Yua secretly doubts Gai's vision for the future, but she is unable to do anything about it.
  • Aruto Hiden/Kamen Rider Zero-One: Gai considers Aruto as his rival and secretly monitors his progress for his own projects. During their first meeting, Gai coerces Aruto to sell Hiden Intelligence to him. Gai also discreetly undermines Hiden Intelligence's public image by setting up rampaging Magias across the city after the threat of MetsuboJinrai.net ends, before exclaiming that ZAIA will buy Hiden to solve the Humagears problem, furthering the animosity between the two CEO's. Gai seems to see Aruto as a nuisance, due to his naivete and overly positive views on Humagears and Humantity; on top of his dismay over Korenosuke entrusting his company to Aruto. In truth, Gai only see Aruto as an obstacle to take over the Hiden Company as after he had learned the potential of the Humagear, Gai had planned to manipulate them for his personal business.
  • Isamu Fuwa/Kamen Rider Vulcan: Gai doesn't care about Isamu, as he isn't part of ZAIA's plans for now. When Yua asks him about Assault Wolf's dangerous side effects, he says that all they can do is to leave him alone and watch him. Isamu seems suspicious of ZAIA and their goals, and in turn, Gai. He is also aware that Yua is heavily affiliated with the CEO. After confronting Yua for what he plots with ZAIA, Gai considers him another enemy, labeling him a "stray dog" although Gai still considered him a lesser threat. But Isamu later able to pressure him during the exposure of the Raidriser's origin, turning Gai's opinion and attempted to turn him into his 'pet'.
  • Korenosuke Hiden: Gai idolizes Korenosuke due to his vision of the future and at some point took a picture with him. However, Gai is heavily disappointed in Korenosuke's reliance of developing Humagears and decision to entrust Hiden Intelligence to Aruto, which he deems as a foolish decision. In truth, Gai only admired the business opportunities provided by Humagears, but did not respect Korenosuke's support for them and their potential evolution.
  • The Ark: Gai created the Ark and had it fed with information regarding criminal psychology and human history including all of its wars. This resulted in the Ark concluding that humanity must be eliminated because its continued existence would lead to the end of all other lifeforms. The Ark's misanthropic view led to the foundation of MetsubouJinrai.net, as well Gai exploiting the A.I.'s potential for his own sinister ends. Despite this, the Ark itself is hostile towards its own creator, as shown when it took control of Zero-One MetalCluster Hopper to attack him.
  • Horobi: Horobi curses Gai for having exploited the Ark for his own selfish purposes.

Behind the Scenes



  • His first name Gai () is a numeral character which means 1020 in Japanese.
  • Kamen Rider Thouser's name is derived from the English word "thousand".



  • Gai Amatsu becoming Kamen Rider Thouser had been foreshadowed several times throughout the series: 
    • His corporation's origin was mentioned in episode 4 before him and the company were fully revealed on the following episode.
    • On his first appearance, he stated that his succession rate was one thousand percent.
    • In episode 13, Gai had mentioned the possibility of Thouser challenging Zero-One Shining Hopper's strength.
  • Thouser's Awaking Lancer and Amazing Trident horns crossing into a crown is similar in design with Kamen Rider Cronus's Chrono Blade Crown.
    • An appropriate parallel between Gai and the first Cronus is their manipulation skills only worked without being personally involved in the orchestrated events.
  • So far, he's the only Rider in-Series to have his company name being presented by as a transformation announcement. 
    • Most likely for egotistical reasons, he is in some ways similar to Ryoma Sengoku and Kuroto Dan to that extent.
      • This even further be proved similar as Gai had admitted that he planned to manipulate humanity and Humagear for his business to Yua, becoming the top like a God.
  • So far he's the only Rider in-Series to have his finisher prelude texts in English rather than in katakana or kanji.
    • Humorously, he is the only Rider in-series to have his finishers copyrighted.
      • This is even more ironic in which most of his finishers are simply copying other riders powers.
  • Even though Gai is 45 years old, which makes him the oldest of the six Riders in-series, his actor, Nachi Sakuragi, is 22 years old.
  • In some ways, Gai serves as a foil to Jun Fukuzoe, especially how they viewed Aruto's role as CEO. Fukuzoe deemed Aruto unfit to be CEO of Hiden Intelligence and wished him to fail and is not above resorting to morally-questionable methods to keep the company's image clean. Though he comes to recognize Aruto's efforts as the series progress. Whereas Gai seeks to undermine Hiden Intelligence and its public image by secretly manipulating both the heroes and villains alike in the shadows and plans take over Hiden Intelligence once he makes his presence known to Aruto.
    • Gai is similiar to Swartz and Evolt as well, especially how they manipulate events in the past, leading to tragic consequences (Gai's reprogramming to the Ark triggered Daybreak Accident, Swartz's actions on the bus in 2009 that killed adults and endanger their children to seek a "worthy" king, and Evolt opening Pandora's Box that triggering the Skywall Tragedy) affecting protagonists, and they manipulate the events from shadows in present, though they lose a composure if protagonist does unexpected things (Aruto gaining control over MetalCluster Hopper form, Ohma Zi-O being too overwhelming for Another Decade, and Sento's Genius Form immunity to Evolto's Lost Bottle).



Icon-zero-one.png Kamen Rider Zero-One
Kamen Riders
Soreo Hiden - Aruto Hiden - Isamu Fuwa - Yua Yaiba - Jin - Horobi - Ikazuchi - Naki - Gai Amatsu - Ark - Esu
Movie-exclusive: Soreo Hiden - Esu - Bell - Kamen Rider Abaddon - Leon Arkland
Stageshow-exclusive: Azu - Little Assassin
Hiden Zero-One Driver - A.I.M.S. Shotriser - MetsubouJinrai Forceriser - Zetsumeriser - ZAIA Thousandriver - Cycloneriser - Raidriser - ZAIA Slashriser - Ark Driver - Hiden Zero-Two Driver - Zetsumetsu Driver - Eden Driver - Abaddoriser - MetsubouJinrai Driver
Progrisekeys - Progrise Holder - Progrisekey Connector - Hiden Risephone
Attache Calibur - Attache Shotgun - Attache Arrow - Breaking Mammoth - Giger - Buaruku Sabers - Authorise Buster - Assault Grip - Thousand Jacker - Progrise Hopper Blade - ZAIA Spec - Nihon Ookaminotsume - Claw Assault
Hiden Intelligence: Korenosuke Hiden - Soreo Hiden - Jun Fukuzoe - Sanzo Yamashita
Humagears: Izu - Shesta - Soreo Hiden - Wazu Nazotoku - Subaru - Hakase Bot - Fukkinhoukai Jiro
Legend Riders: Sougo Tokiwa - Geiz Myokoin - Woz - Tsukuyomi
Humans: Norio Uozumi - Go Sakurai - Satoshi Sakurai - Choichiro Ishizumi - Seiji Tazawa - Satō - Yuta Yomura - Isao - Shinya Owada - Ikkei Amatsu
Humagears: Mageana - Ikkan Nigiro - Anna - Mashirochan - Dr. Omigoto - Z #5 - Delmo - Love-chan - Midori
A.I.s: Zea - Zat - Ai-chan - Thouser
Ark - Horobi - Naki - Jin - Ikazuchi - Little Assassin - Azu
Monsters: Berotha Magia - Kuehne Magia - Ekal Magia - Neohi Magia - Onycho Magia - Vicarya Magia - Gaeru Magia - Mammoth Magia - Dodo Magia - Arsino Magia
Footsoldiers: Trilobite Magia - Dodo Magia Chick - Battle Magia
Other Villains:
Finis - Will
Gai Amatsu - Williamson Yotagaki
ZAIA Spec Representatives: Rentaro Tachibana - Tatsumi Arayashiki - Naoto Ichimori - Takeshi Homura - Masamitsu Yuto
Other: Daiki Kyogoku
A.I.M.S.: Isamu Fuwa - Yua Yaiba - Naki - Eida - Ono - Degawa - Shida - Eifuku - Ito
Monsters: Crushing Buffalo Raider - Splashing Whale Raider - Dynamaiting Lion Raider - Storming Penguin Raider - Scouting Panda Raider - Fighting Jackal Raider
Footsoldiers: Invading Horseshoe Crab Raiders
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