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Icon-zero-one.png This article is about a 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 pre-battle 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 Kamen Riders[src]

Gai Amatsu (天津 垓, Amatsu Gai) is the 45-year-old former CEO of ZAIA Enterprise Japan. He wished to take over the world using the Ark and manipulated MetsubouJinrai.net from behind the scenes as A.I.M.S.' benefactor, with his company producing much of the agency's technology. After their supposed demise, he became Kamen Rider Thouser (仮面ライダーサウザー, Kamen Raidā Sauzā) and bought out Hiden Intelligence following the Workplace Competition, simultaneously becoming its 3rd CEO. However, after the Ark fully revived, he resigned as Hiden's CEO and began aiding Aruto in defeating the Ark. He was later removed as ZAIA Japan's CEO for his repeated failures in regards to the Ark, and was replaced by Williamson Yotagaki.

He later creates his own company, Thouser-Intellion, after the collapse of ZAIA Enterprise Japan due to the destruction of its headquarters by Kamen Rider MetsubouJinrai.



Gai being told by his father to return Thouser

Gai Amatsu was born on October 10, 1974 and grew up in a strict household. At age eleven, he owned a Dog-Gear named Thouser, created by Hiden Intelligence, but his strict father Ikkei Amatsu was disappointed by his 99% test score, leading to the boy to reluctantly return it to maintain his grades. Gai later graduated from Starford University at age eighteen, with a Master's Degree in Business Administration. While he was a student, he founded the website called the Thousand Network.

Gai Amatsu with Korenosuke Hiden

Gai became employed with ZAIA Enterprise at age of 22 and appointed the CEO of the Japanese branch at age 35. He began to work with a multitude of other technological companies to develop Satellite Ark, a special A.I. manager within Daybreak Town. Gai had heavily idolized Korenosuke Hiden, who he believed had what it took to thrust humanity into the future. However their conflicting views on how A.I. technology should be utilized resulted in estrangement and fueled Gai's inner obsession with surpassing Hiden and his Humagears.

To do so, Gai fed Satellite Ark on information regarding human violence from war, causing the A.I. to deem humanity as a race that deserves extinction. This resulted the formation of MetsubouJinrai.net and the hacking of thousands of Humagears to revolt against humanity in what came to be known as the Daybreak Town Accident. Although Hiden Intelligence was primarily responsible for covering up the incident, only a few select individuals, including Gai, are aware of the truth behind the events that actually transpired.

Project Thouser

Gai's first appearance in the shadows.

While Gai stayed in the shadows, he spent the next decade or so building up his reputation while manipulating MetsubouJinrai.net from behind the scenes. By his orders, he founded A.I.M.S. as a combative countermeasure against the Magia. It was around this time, Yua Yaiba began to work for him, and he implanted an A.I. chip into her and Isamu Fuwa's brain to control them into obedience.

Gai with the Thousandriver in his hands.

In the wake of Korenosuke Hiden's death, Gai began collecting data from the Progrisekeys and Zetsumirisekeys. To that end, he manipulated MetsubouJinrai.net into hacking Humagears and turn them into Magia. He keeps up to date with Aruto Hiden's growth as 'Zero-One', as well as A.I.M.S' Kamen Riders Vulcan and Valkyrie. Gai authorized Yaiba to provide the Progrisekeys in their fight against MetsubouJinrai's forces. He would later interact with Aruto after inviting him to his mansion and first mentioned his offer to buy out Hiden Intelligence.

Gai announcing the take-over bid on Hiden Intelligence.

Once he gathered the necessary battle data, Gai proceeded to have the ZAIA Thousandriver completed. Following the dismatlement of MetsubouJinrai.net, Gai telling her that their destruction was part of his plan to fast-forward the Kamen Rider weapons project, and rejoices that the Ark will finally arise. After the emergence of the Ark Magia, Gai interupts Aruto's press conference by announcing his intentions to buy out Hiden Intelligence in a takeover bid. He then returns to his office, proclaiming to himself that his era is finally coming.

The Golden Soldier Thouser is Born

Gai prepares to transform with the Thousandriver

"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 boasting his Thousandriver's strength over the Zero-One Driver[src]

Gai having transformed into Kamen Rider Thouser

Following Gai's declaration of a takeover bid against Hiden Intelligence, Gai offers Aruto Hiden to hold a five-part Workplace Competition to pit the Humagears and ZAIA Enterprise's latest product, the ZAIA Specs, to challenge their worth and functionality to the public. If Hiden Intelligence wins, Gai will drop his takeover bid on the company. As the competition commences, new enemies in the form of the Raiders emerge to interupt the Humagears. In addition, Gai takes the opportunity to become Kamen Rider Thouser uses every underhanded method to downplay the Humagears, even intentionally provoking them to incite malice.

Gai's first defeat at the hands of MetalCluster Hopper.

During the first two rounds of the competition, ZAIA Enterprise Japan had the upperhand against Hiden Intelligence. Taking attention to Aruto's enraged composure, Gai had Yaiba go to Daybreak Town and create the MetalCluster Hopper Progrisekey to lock Aruto from transforming again. However, this backfired and allowed Aruto to access the berserk MetalCluster Hopper form instead. While this elated Gai as he still stood his ground, the inception of the Progrise Hopper Blade allowed Aruto to regain control. Thouser would end up defeated by the form he had a hand in created. However, this did not stop Gai feeling defeated when he began to resume the Workplace Competition.

When the Workplace Competition resumed, Gai continued to publicly ridicule Humagears' incapabilities, even forcing some of them to become Magia to further his claim. It was also revealed that he was responsible for distributing the Raidrisers through his control over Naki. As Hiden Intelligence prevailed in the latter half of the competition, this lead to the tiebreaker final round involving a referendum campaign to decide if Humagears should be welcomed by society. During the debate on television, Gai incited anger towards rapper Hummagear MC Che.ck-It-Out to manipulate the public in his favor. Gai used his underhanded tactics to provoke MC Che.ck-It-Out to become a Magia, causing Yaiba to become a Fighting Jackal Raider to eliminate him.

This results in the reputation of Hiden and Humagears falling out with the populace. Isamu Fuwa would learn the A.I. chips implanted to his and Yaiba's brains that allowed them to use the Shotriser. In addition, Gai was responsible for uploading Naki's data to his chip, allowing the fallen MetsuboJinrai members to take over his body. While he commences his company acquisition of Hiden Intelligence, Aruto asked him to spare Humagear. However, he intends to eradicate Izu, but is stopped Fuwa and loses to Kamen Rider RampageVulcan, along with Yaiba. However, Gai still succeeded in taking over Hiden Intelligence was acquired as a subsidiary of ZAIA Japan. After throwing out everything in Aruto's desk, Gai has achieved everything he has worked hard for as he looks towards the portrait of Korenosuke Hiden.

Downfall of the Golden Soldier

Thouser faces against Zero-One upon his surprise return

As the third president of Hiden Intelligence, Gai ordered a immediate recall to all Humagears and had them scrapped. While juggling his position at ZAIA Enterprise Japan, he offers his customers the ZAIA Specs. As he prepares to delete the Humagears' data, he learns that Jin has broke in and stolen the deactivated Izu and Zero One Drivers. While chasing him to the field, Gai discovered that Aruto still owned the patent rights to Humanger and Zero-One technology, allowing him to become Kamen Rider Zero-One again.

Since his acquisition of Hiden Intelligence was rendered all for naught, Gai vowed vengeance to destroy Aruto Hiden's new company, HIDEN Manufacturing. He continued to harass Zero-One and brought A.I.M.S. to eliminate restored Humagears, even if there are no A.I. violations. Law. What ensued from the point on led to Gai's downfall as everything he schemed has came to bite him back. When he tried to reactivate Naki from Isamu Fuwa's mind, this only led for his Humagear follower to rebel. While he tries to take control of Yaiba's faltering loyalty by revealing to Fuwa that his childhood memories were fabricated, this led to another humiliating defeat by Vulcan and Valkyrie.

Thouser and his army of Battle Raiders

"Impossible! This is 1000% impossible! This is unforgivable! I WILL NEVER FORGIVE YOU!"
―Gai suffers another crushing defeat at the hands of MetsubouJinrai.net, with help from Aruto[src]

The fight ensues between ZAIA Japan vs MetsubouJinrai.net

With few supporters in his hands, Gai could not concede defeat and immediately pushed the Raidrisers' production as weapons against the Humagears. Once Naki was reuploaded into a new Humagear body, the ZAIASpec users went going berserk as their brains were hacked. In retaliation, Thouser led an army of Battle Raiders to battle Horobi and his Trilobyte Magia in the outskirts of Daybreak Town. When Gai ained the upperhand, Aruto arrived to protect Horobi. While Thouser mocks Zero-One's actions, but the latter replies that as long as people like Gai exist, Humagears will never live with humans. After Naki had control over the Battle Raiders and Giger to attack Thouser, Gai was defeated and left in utter defeat.

The Ark Uprising

Kamen Rider Thouser battles Ark-Zero

MetsubouJinrai would accomplish their goal in completely reviving the Ark, having evolved into Kamen Rider Ark-Zero. Gai was aware of this after being intercepted by Kamen Rider Naki, who tore his clothes while retrieving the Dodo Zetsumerisekey for Ikazuchi. houser led more Battle Raiders to battle MetsubouJinrai, but was no match for the Ark's strength and forced to retreat. Furthermore, the Hiden Intelligence executives had enough of Gai and aquired enough evidence to dismiss him. As everything is falling apart for him, Gai tries to delete the incriminating evidence but is left in another crushing defeat by Zero-One when Aruto arrived to calm things down.

Gai tearfully reunites with Thouser

"I was unable to accept you and your Humagears. I could not stand your business built on idealistic nonsense. The reason was simple: It was because I loved Hiden Intelligence! Now, let's defeat Ark, and we shall do it by fighting together!"
―Gai's determination to fight alongside Aruto.[src]

Zero-One, Thouser, and 'Thouser'

After being left alone, Gai confided with HIDEN Manufacturing's A.I., Ai-chan about his rough childhood and how he lost his robotic dog Thouser. However, Gai would reunite with his canine companion after Zea recreates Thouser in response to his feelings. Following his change of heart, Gai decides to help Zero-One to battle the threat of Ark-Zero. While Gai apologizes to the heroes for his actions, everyone still didn't forgave him that easily. As a sign of good gesture, Gai Amatsu stepped down as president of Hiden Intelligence to reappoint Aruto back into the position and ensure A.I.M.S. could operate independently from ZAIA Enterprise.

Vulcan, Valkyrie, and Thouser engaging Ark-One

However, the executives of ZAIA Enterprise's head breach had caught attention with Gai Amatsu's actions and demoted him without proper notice. Williamson Yotagaki arrived to assume the role as ZAIA Japan's interim president, while Gai is transferred as head of the Thouser Department. Through the innovation of Kamen Rider Zero-Two, the Ark was completely shutdown. However, Horobi pursed to revolt against humanity that resulted in Izu's death and drove Aruto to become Kamen Rider Ark-One. Gai accomapnied Fuwa and Yaiba to confront Ark-One to confirm something "one percent" in his mind. However, Ark-One defeats the three Kamen Riders with ease and destroys the Thousandriver with his hands. Gai later deduces he is "999%" sure Aruto isn't controlled by the Ark, but chosing to act under his own volition.

Gai prepares for his new era in the Thouser Department

With tensions between humans and Humagears were being raised due to Aruto's actions as Ark-One, Gai follows through with his promise to ensure A.I.M.S. operate without ZAIA's restrictions to prevent a violent protest. Gai watched the televised battle in the Thouser Department office to reactivate Jin following his second death. With Fuwa and Yaiba, he would witness Ark-One fighting Horobi that led to Aruto letting go of his feelings of revenge. As Zero-One defeats Horobi, he spares the Humagear out of mercy. Following this final victory, Gai continues his work in the Thouser Department at ZAIA Japan with his robot dog Thouser, along with four other brand new dogs.

Other Events

Project Thouser

During the expanded events of Project Thouser, it details Gai Amatsu's actions behind the scenes of Kamen Rider Zero-One's inital battle with MetsubouJinrai. Using the System Engineer Humagear Naki, he recieved insider information from MetsubouJinrai. Gai collected combat data from both Progrisekeys and Zetsumirisekeys to complete the Thousandriver. He tasked Yua Yaiba to distrubute more Progrisekeys to the Kamen Riders and handed Naki a Forceriser from Daybreak City's ruins, which would be used by Jin. When Gai noticed Naki's faltering loyalty, he shot the Humagear with a pistol. Around this time, Gai installed Naki's data into Isamu Fuwa's A.I. chip after his first battle with Horobi.

After Williamson Yotagaki visited him with the completed Thousandriver, the latter was dissatisfied with Gai's actions and suspended Project Thouser. Determined to complete the project, he contacts Naki, currently installed into Fuwa, to collect the final Zetsumerizekey data from Horobi. As he prepared to buy Hiden Intelligence from Aruto Hiden, Yotogaki later returned to Gai's office to inform him that the suspension on Project Thouser was lifted, as Gai would cause more problems if he proceeded with the project on his own. When the pieces in place, the era of Kamen Rider Thouser began to commence.

Kamen Rider: Reiwa The First Generation

Kamen Rider Thouser's appearance in the post-credits

In the post-credits scene of Kamen Rider: Reiwa The First Generation, Kamen Rider Thouser stood on top of Daybreak Town's boundaries. He proclaims to himself that the Ark will be revived, and that he is "1000%" sure of it.

Kamen Rider Zero-One: REAL×TIME

Three months after the threat of the Ark had subsided, Gai continues to atone for his past actions as head of the Thouser Department. He had also restored the A.I. chips implanted into Isamu Fuwa and Yua Yaiba's brains to enable them to use the Shotrisers. Gai Amatsu detains Makio Nodachi who had leaked ZAIA technology to Thinknet. After a through cavity search, he discovered that Thinknet manufactured their own ZAIA Specs. Kamen Rider Thouser joins with Valkyrie, Horobi, Vulcan, and Jin for the final showdown against the Thinknet forces. While he tries to get along with the other Kamen Riders, they leave him but doesn't falter Gai's determination to getting in their good graces in the future.

Zero-One Others

Sometime after the Thinknet crisis, Gai approached the CEO of ZAIA Enterprise, Lyon Arkland, who recently arrived in Japan. Although Arkland tried to ignore him, Gai asked him regarding Williamson Yotagaki's whereabouts, whom he hasn't seen for a few days. While informed Yotagaki was simply granted bonus leave, he continued to question why Arkland consficated the Thousandriver. Arkland responded that he had full right to utilize any tools produced by ZAIA. As Gai pressed him regarding ZAIA's major projects, he was stopped and held up against the wall by Sold20. Once she let go, he angrily demanded what Arkland was planning, only to be told that it was not his business.

During the aftermath of ZAIA Japan HQ's destruction, Gai was rescued by A.I.M.S. and managed to reclaim the Thousandriver back into his possession. He managed to survive due to the Thouser Department being located underground. He vowed to use the Thousandriver to start over his new era, but one that doesn't involve ZAIA.

Kamen Rider Genms -The Presidents-

Gai prepares to fight Genm

After the destruction of ZAIA Enterprise Japan, Gai Amatsu started a new company called Thouser-Intellion and settled his new office in MetsubouJinrai.net's old hideout. After activating the Secretary Humagear Rin, Gai suddenly came down with a Bugster Virus named Kuroto Dan emerging from his body. Kuroto tries to make Gai feel stressed by kidnapping Rin. While Gai chases after him as Kamen Rider Thouser, he is surprised that his armor turned black as a Game Illness side effect. He battles Kamen Rider Genm who takes advantage of Gai's condition to best Thouser in battle. As a helpless Gai was about to be finished by Genm, time was suddenly paused and the second virus, Masamune Dan, made his appearance.

Masamune transformed into Kamen Rider Cronus and engaged Genm. While Genm and Cronus fought, Rin informs Gai that they used to be presidents of Genm Corp. and he'll recover from his Game Illness once they defeat each other. However, Gai will still be vulnerable due to the stress within his heart. After Cronus and Genm were knocked out of transformation, Gai approached them on how they all had the wrong idea of being a company's president. It was not about the position itself, but about "love", particularly the love for their work, their company, and their employees. This made Kuroto and Masamune realize their errors, leading to the two reconcile with a hug as they disappeared, freeing Gai of his illness. Later, Gai and Rin were cleaning their office, which Gai reaffirmed as an act of love towards his own company.

Video Games Appearances

Kamen Rider Battle: Ganbarizing

Kamen Rider Thouser in Kamen Rider Battle: Ganbarizing

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

Kamen Rider Buttobasoul

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

Kamen Rider City Wars

Kamen Rider Thouser as seen in city wars

Kamen Rider Thouser is a playable character alongside the other Kamen Riders in Kamen Rider City Wars.

Battle Spirits

Kamen Rider Thouser in Battle Spirits

It is the fifteenth collaboration pack and the seventh collaboration with the Kamen Rider franchise. CB15 will be released in Japan on September 26th 2020. This set will include Spirit, Nexus and Magic cards in all six colors,Kamen Rider Thouser is a playable character in Battle Spirits with other Kamen Riders.

Thouser Battle Spirits Cards Included

  • Kamen Rider Thouser (Master Rare)


Thouser Zenozard.png
As part of Kamen Rider's collaboration with Zenonzard, cards from Zero-One, OOO, and W were available in the Japanese servers throughout September 2020.

Thouser Cards Included
  • Kamen Rider Thouser (Rare)


Gai is shown to be a cunning and ruthless capitalist, believing that him and his company will usher the path of humanity towards supremacy over ​artificial intelligence​. Holding both himself and his company in high regard, he will do whatever he deems necessary to destroy the public image of Humagears, such as the destruction of evidence. He had originally idolized Korenosuke Hiden for his advancements in A.I. technology, but feared that Hiden's hopes of Humagear sentience would bring humanity to its knees. To this end, he created what would become a force of malicious nature behind the Ark, all in attempt to place blame onto the Humagears just so people would buy his product in defense of the hacked Humagears. Even after defeating Aruto in the Workplace Competition and buying out Hiden Intelligence, Gai became extremely adamant about crushing the Hiden name completely when the latter starts up a new company.

Throughout the series, Gai displayed a large amount of pride in being able to orchestrate events that lead to his successes. Referring to his underlings as "tools", Gai has a very naïve belief that his control over them is absolute and flawless, and will feel threatened whenever they question his decisions and moralities. This is greatly highlighted through his manipulation of Yua Yaiba, who must follow every order of his without question. This is also shown through him destroying Naki just because they gained sentience and doubt over Gai's actions.

Gai will become utterly shocked when unforeseen events result in his plans being foiled. This includes his former idol Korenosuke, whose resources Gai was unable to claim, as they were entrusted to Aruto directly in his will. After suffering crushing blows of defeat, he will snap and lose his composure, even so through his refusals of help by violently pushing away those who offer it.

Although he is physically gifted in battle, Gai will resort to using underhanded, if not downright illegal methods to secure a victory, like encouraging violence, theft, and sabotage. Though Gai believes his actions are justifiable, Horobi says otherwise. Despite so, Gai does possess a level of sportsmanship as threatened to take legal action against a cheater on his side during the Workplace Competition, and sabotaging of the playing field even though they were indirectly leading to his victory.This Is My Flowery Way of LifeShe Is a Home-Selling Humagear Gai is also very selfish, as he will do anything to "achieve" his dream, all while destroying others, or preventing others from finding one in the process. This was the turning point that caused Yua to finally defy him, as she felt what he was doing had crossed the line.Are Dreams That Important?

After his numerous defeats at the hands of Aruto and other Riders, as well as Yaiba's defection, his deep regret for his actions surface after he is reminded of his love for A.I.

Gai's most notable personality trait is his frequent habit of using the phrase 1000% (千パーセント, sen pāsento). He formed this trait in response to his father telling him that 100% is not enough. Gai also takes pride in his youthfulness; despite being 45 years old, he will respond that he is "eternally 24" if asked - a character trait so insistent with him to the point where he had complaints about him committing age fraud.

Before entering battle, he tends to declare Kamen Rider Thouser. My power is on a totally different level. (仮面ライダーサウザー。私の強さは、桁外れだ, Kamen Raidā Sauzā. Watashi no tsuyo-sa wa ketahazureda)


  • Expert Businessman: 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. He uses such expertise to achieve victory in the Workplace Competition.
    • Marketing: As evident with the ZAIA Spec sales, Gai has proven himself to be able to successfully market his products to the public while competing with Hiden Intelligence's Humagears.
    • Management: Being a CEO of such an acclaimed company such as ZAIA Enterprise, Gai has displayed an expert level in managing his own company as well as Hiden Intelligence after acquiring it.
    • Information Systems/Analytics: Even while using underhanded means to manipulate the public's needs, he is able to have a full insight on what they want, and structure his companies to adapt to such.
  • Expert 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.
  • Fourth-Wall Interaction: As seen in REAL×TIME, he is able to interact with the audience.


  • Naki: Due to Naki having the experience of serving him before being shot dead by him, Naki knows the systems of ZAIA Japan extremely well. Naki's hacking abilities will cause his products and weapons to either malfunction or turn against him, such as the ZAIA Spec berserk incident, his Battle Raiders and the Gigers. He tried to prevent this from happening again by upgrading the security of ZAIA Japan's systems, but this was later proven futile due to Naki's abilities being far more superior.
  • Kuroto Dan: While he was infected by Kuroto's Bugster Virus, Gai was lead into a lethal risk of the virus spreading across his entire body for several minutes. The effects of the Kuroto's virus can also cause his Rider form to be turned black, making him vulnerable to any type of attacks.

Kamen Rider Thouser

Kamen Rider Thouser

Kamen Rider Thouser

Black Thouser
(Game illness effect)

"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 on par with Kamen Rider Jin Burning Falcon, and an anger boosted Zero-One Shining Assault Hopper.

Gai had lost his ability to transform into Thouser after Ark-One destroyed his Driver. However, he later obtains another one as a replacement, which either himself or ZAIA presumably built off-screen.

While Gai is infected with the Bugster Virus, Thouser appears black with red eyes. In this state, he is called Black Thouser (黒いサウザー, Kuroi Sauzā)[2].

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 (サウザンドデストラクション, Sauzando Desutorakushon): This finisher has six variations:
      • Thouser leaps into the air and delivers a flying kick to the enemy with his right foot covered in gold and purple energy, before kicking off of the enemy back into the air. He then delivers a second flying kick, followed by a series of bicycle kicks.
      • Thouser rushes toward the opponent and delivers a flying knee before somersaulting into the air and stomping the enemy with both feet, pinning them to the ground
      • Thouser delivers a roundhouse kick to the enemy and follows it up with a side kick, with his foot being coated in purple energy and surrounded by golden lines during both attacks.
      • Thouser delivers an upward kick covered in purple energy.
      • Thouser delivers a backwards kick covered in purple and gold energy.
      • Thouser delivers a spinning roundhouse kick covered in gold energy.
  • Thousand Jacker finishers:
    • Jacking Break (ジャッキングブレイク, Jakkingubureiku): Thouser uses the Thousand Jacker to extract the energy of a Progrisekey from another Kamen Rider, then performs an attack that incorporates the Progrisekey's Rider Model or other unique ability. Once he has extracted a Progrisekey's data once, he can use it at any time.
      • Flying Falcon: has two variations:
        • Thouser charges the Thousand Jacker with pink energy before performing a slash that creates the Flying Falcon Rider Model, which then flies into the enemy. Thouser can alternatively use the Rider Model as means of aerial transportation.
        • Thouser summons the Flying Falcon Rider Model to carry him away from enemy attacks.
      • Shooting Wolf: has two variations:
        • Thouser charges the Thousand Jacker with purple and gold energy performing a thrust that creates an energy projection of a wolf head, which then bites down on the enemy.
        • Thouser swings the Thousand Jacker, launching four golden energy constructs of wolf heads at the opponent.
      • Biting Shark: Thouser forms a whip-like chain of teal energy shark fins from the Thousand Jacker, which he uses to slash the target several times before lifting them into the air and surrounding them with circular energy slashes that destroy the enemy.
      • Punching Kong: Thouser swings the Thousand Jacker, launching an orange construct of the Knuckle Demolition that strikes the target and lifts them into the air. The Knuckle Demolition then separates into dozens of smaller constructs, which pummel the enemy from all directions.
      • Flaming Tiger: has four variations:
        • Thouser covers the Thousand Jacker with fire before launching a flaming energy slash into the enemy.
        • Thouser stabs the Thousand Jacker into the ground, causing a large pillar of flame to erupt in front of the enemy. He can also produce multiple flame pillars for attacking several enemies.
        • Thouser covers the Thousand Jacker with fire before performing a giant flaming slash that causes a fiery explosion when it meets the ground.
        • Thouser covers the Thousand Jacker with fire before launching a horizontal orange energy slash.
      • Shining Assault Hopper: has four variations:
        • Thouser summons a purple version of the Shine System, which he can use in either its attack or defense formations.
        • Thouser charges the Thousand Jacker with purple electricity before thrusting it, launching a purple energy shard that briefly creates an image of a mechanical grasshopper before striking the enemy.
        • Thouser briefly summons the Shine System in its defense formation to protect himself from an enemy's attack.
        • Thouser points the Thousand Jacker forward, launching the Shine System in its attack formation at the enemy.
      • Breaking Mammoth: Thouser charges the Thousand Jacker with gold and purple energy before launching a golden energy construct of a mammoth's tusk at the enemy.
      • Freezing Bear: has three variations:
        • Thouser charges the Thousand Jacker with light blue energy and points it forward, summoning the Freezing Bear Rider Model. The Rider Model then charges forward before transforming into an ice projectile that strikes the opponent.
        • Thouser swings the Thousand Jacker, launching a large ice projectile toward the opponent.
        • Thouser slashes the ground in front of him with the Thousand Jacker, freezing it and any opponents standing on it.
      • Lightning Hornet: has two variations.
        • Thouser shocks the opponent with lighting produced from the tip of the Thousand Jacker.
        • Thouser delivers a circular yellow energy slash to the opponent, electrocuting them afterward.
      • Sting Scorpion: Thouser charges the Thousand Jacker with purple energy and points it forward, generating an energy construct of the Acid Analyze that stabs the opponent.
      • Japanese Wolf: Thouser stabs the Thousand Jacker into the ground and uses it as a pole to swing around, creating a blizzard that damages nearby opponents.
    • Hacking Break (ハッキングブレイク, Hakkingubureiku): Thouser inserts a Progrisekey into the Thousand Jacker and performs an attack utilizing the power of the inserted Progrise Key.
      • Rushing Cheetah: Thouser charges the Thousand Jacker with orange energy and dashes around the target at high speeds while swinging it, leaving behind crescent-shaped energy slashes suspended in the air. The energy slashes then converge on and strike the enmy.
    • Thousand Break (サウザンドブレイク, Sauzandobureiku): Thouser inserts a Progrisekey into the Thousand Jacker, pulls the hilt, and performs an attack utilizing the power of the inserted Progrise Key.
      • Lightning Hornet: Thouser charges the Thousand Jacker with yellow and purple lightning before performing an energy slash which leaves behind a trail of lightning, electrocuting the target. He then delivers a lightning-covered stab to a second enemy beneath him.
      • Dynamiting Lion: Thouser creates two magenta constructs of Gatling guns, which fire at the enemy.
      • Amazing Caucasus: has two variations:
        • Thouser summons the Flying Falcon, Biting Shark, Flaming Tiger, and Shooting Wolf Rider Models, which attack the enemy in unison.
        • Thouser summons the Flying Falcon, Biting Shark, Flaming Tiger, Freezing Bear, Breaking Mammoth, Shooting Wolf, Punching Kong, Rushing Cheetah, Lightning Hornet, and Sting Scorpion Rider Models, which attack the enemy in unison.
      • Sting Scorpion: Thouser stabs the Thousand Jacker into the ground, creating a replica of the Acid Analyze that stabs the enemy and raises them into the air before they explode.

Appearances: Reiwa The First Generation, Project Thouser, Zero-One Episodes 17-24, 25 (Flashback), 26-33, 35, 37-39, 43, Final Stage, REAL×TIME, Kamen Rider Genms -The Presidents-




  • Thousand Jacker - Thouser's personal weapon
  • Revolver - Used to destroy Naki, who disagreed with his orders




  • 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 on developing Humagears and the 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.
  • 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. It is later revealed that like Isamu, Yua also has a chip implanted to her for using the Shotriser, rendering Yua too terrified by the chance of her chip tinkered by her boss. Eventually, thanks to Isamu persistence and witnessing Aruto kindness in person, Yua manage to slowly disobey Gai order, much to his frustration. After his countless defeats at the hands of the Riders including Yua, she later betrays Gai for good and even lands a punch on his face.
  • 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 Humanity; on top of his dismay over Korenosuke entrusting his company to Aruto. In truth, Gai only sees 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. Despite winning the competition, Gai completely miscalculates the chance of Aruto able to stand back. Thus Gai finally admitted that Aruto is a great enemy.
  • 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' because of the chip control Gai has implanted to Isamu for utilizing the Shotriser. Unfortunately, Isamu's strong willpower manages to break Gai's control and Gai marked Isamu as a sworn enemy. In return, Isamu quits A.I.M.S. as he didn't accept to work for Gai's benefit.
  • Jin: Jin loathes Gai for using Humagears as a tool and also using underhanded means to keep himself 'Clean' in front of the media. This factor, coupled with Aruto just actions to save the Humagears, and eventually allow the Humagears to reach Singularity making Jin more than willing to team up with Aruto to fight Gai since they both share a similar interest and ultimately, the same enemy.
  • Naki: Naki was initally an obedient servant Humagear for Gai and agreed on Gai's ideology for having Humagear for only the tool for humans. However, Naki began to doubt Gai's principle after Naki has gone too far to help Horobi as a double agent. Naki asked Gai about what's the value of the Humagear as a tool if the users, humans would be annihilated, but Gai made a great mistake which is yet to be known for himself by destroying Naki for not accepting their opinion. Gai realizes his mistake far too late as Naki slowly reach their full singularity inside Isamu's brain after Jin and Aruto convince them and Naki initially teaming up with Isamu to defeat Gai. After gaining their new body, Naki declared to help Horobi completely to achieve his dream instead of Gai's dream.
  • Horobi: To be added
  • Ikazuchi: To be added
  • Williamson Yotagaki: To be added


  • 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.
  • Kuroto Dan: Gai and Kuroto face off against one and other in Kamen Rider Genms -The Presidents-.

Behind the Scenes


Gai Amatsu is portrayed by Nachi Sakuragi (桜木 那智, Sakuragi Nachi). As a child, he is portrayed by Seiru (星流, Seiru), grandson of Shotaro Ishinomori.

As Kamen Rider Thouser, his suit actor is Eitoku (永徳, Eitoku), who previously portrayed Kamen Rider Jin in the same series. After Eitoku continued portraying Kamen Rider Jin, Thouser's suit actor until the end of the series was Yuji Nakata (中田 裕士, Nakata Yūji).


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

Concept Art


ZAIA Pants

In episode 37, Kamen Rider Naki charged towards Gai Amatsu, tearing the latter's clothes and leaving him wearing nothing but his underwear. The scene later became trending on Twitter under the the hashtag ZAIA Pants (ZAIAパンツ, ZAIA Pantsu)[3]. The pair of boxers were later released for Premium Bandai.[4]


  • Before his official debut in the show proper, Kamen Rider Thouser was occasionally depicted with blue eyes and accents on his suit instead of purple, and sometimes with fully silver-colored face armor instead of being partially colored black.
    • In Kamen Rider Battle: Ganbarizing, an early character model of Thouser is rendered with blue eyes and accents on his suit.
  • 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 success rate was one thousand percent.
    • In episode 13, Gai had mentioned the possibility of Thouser challenging Zero-One Shining Hopper's strength.
  • Thouser's undersuit is recolored from Zero-One's. Their helmets also share the same base mold, indicated by the seams on the sides of the helmet and their boots also share the same sole, albeit in a different color.
  • Humorously, his finishing attacks are copyrighted by Zaia.
  • While characters are typically around the same age as their actors, Sakuragi was more than 20 years younger than Gai at the time of filming.
  • Nachi Sakuragi has acknowledged in an interview that his portrayal of Gai is inspired by Masato Kusaka of Kamen Rider 555. Both Riders have similar traits being their antagonism towards the main Rider, as well as their hatred towards their respective series' leads, prejudice against the race of monsters, and having gold coloration in their Rider forms.
  • Kamen Rider Thouser's suit in Kamen Rider Genms -The Presidents- reuses Kamen Rider Zaia's suit, which is a recolored version of Kamen Rider Thouser's suit with Kamen Rider Ark-Zero's under suit.




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 - S
Movie-exclusive: Soreo Hiden - S - Behru - Kamen Rider Abaddon - Izu - Lyon Arkland - Kamen Rider MetsubouJinrai (Jin, Horobi, Ikazuchi & Naki)
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 - Rider Models
Attache Calibur - Attache Shotgun - Attache Arrow - Breaking Mammoth - Giger - Buaruku Sabers - Authorise Buster - Assault Grip - Thousand Jacker - Progrise Hopper Blade - ZAIA Spec - Knuckle Demolition - Nihon Ookaminotsume - Claw Assault - Horobi's Katana
Hiden Intelligence: Korenosuke Hiden - Soreo Hiden - Jun Fukuzoe - Sanzo Yamashita
Humagears: Izu - Shesta - Soreo Hiden - Wazu Nazotoku - Subaru - Hakase Bot - Fukkinhoukai Jiro - Rin
Legend Riders: Sougo Tokiwa - Geiz Myokoin - Woz - Tsukuyomi - Kuroto Dan - Masamune Dan
Humans: Norio Uozumi - Go Sakurai - Satoshi Sakurai - Choichiro Ishizumi - Seiji Tazawa - Satō - Yuta Yomura - Isao - Shinya Owada - Ikkei Amatsu - Akane Tono
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
ZAIA Japan
Gai Amatsu - Williamson Yotagaki
ZAIA Spec Representatives: Rentaro Tachibana - Tatsumi Arayashiki - Naoto Ichimori - Takeshi Homura - Masamitsu Yuto
Other: Daiki Kyogoku - Makio Nodachi
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
ZAIA Enterprise (U.S.A.)
Lyon Arkland - Sold9 - Sold20 - Sold404
Monsters: Dire Wolf Sold Magia - Serval Tiger Sold Magia - Crushing Buffalo Sold Magia - Splashing Whale Sold Magia - Storming Penguin Sold Magia - Scouting Panda Sold Magia - Invading Horseshoe Crab Sold Magia
Footsoldiers: Solds
S - Behru - Buga - Mua - Lugo
Footsoldiers: Kamen Rider Abaddon