Sento Kiryu

> *For in-series information, see the Kamen Rider Wiki page for Sento Kirya.*
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 **Character Type:** | Protagonist
 **Affiliation:** | Nascita
Touto Institute of Advanced Matter Physics

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"*Now, shall we begin the experiment?*"
―Build's catchphrase before transforming[[src]]

"*Build Up!*"
―Build's call whenever he changes forms[[src]]

"*The law of victory is set!*"
―Build's catchphrase after finding the winning match[[src]]

"*This is the worst.*"
―Sento's catchphrase whenever things go wrong[[src]]

"*I'm amazing! I'm the best! I'm a genius!*"
―Sento praising his own work[[src]]

"*Best Match kita!*"
―Build upon discovering a Best Match[[src]]

"*What do you think of my invention?*"
―Sento whenever he's being a show off to someone.[[src]]

"*To protect something important...I will rise up as many times as necessary! That's the Build that we created!*"

**Sento Kiryu** (桐生 戦兎, *Kiryū Sento*) is a genius theoretical physicist who experiments with Fullbottles to further enhance his abilities as **Kamen Rider Build** (仮面ライダービルド, *Kamen Raidā Birudo*) to fight against the evil Smash organisms. He is a man with no memory of his past, and fights to find the truth about himself.

## Personality

"*Me and him...We fought to become strength for others. To protect people...we kept rising back up. Even without you...I still have people to protect. For the justice I believe in...I will defeat you!*"
―Sento proving his justice to Blood Stalk.[src] Sento's outstanding traits are his intellect, narcissism, and sense of justice. A genius by all standards, Sento has repeatedly displayed advanced knowledge in physics, mathematics, chemistry, engineering, and cryptography. Sento's polymathism is accompanied by an inflated ego and sharp tongue: he likes to praise himself for his works, and often mocks Ryuga for his comparatively lower intelligence. When Sento gets excited (usually due to a discovery or breakthrough), a part of his hair sticks up.

Sento's greatest trait is his sense of justice. A firm pacifist, he believes that science should be used for the sake of humanity, and harshly opposes using it for war. His selflessness and sense of duty causes him to try and shoulder the burden alone rather than involve others, whether he can carry that burden or not. This altruism intensifies the guilt he feels for his role in creating the Smash and escalating the war. While generally calm and composed, Sento is prone to making poor judgement during emotional turmoil.

Sento has a couple of catchphrases. Before he transforms, he says "Now, shall we begin the experiment?"  (さあ、実験を始めようか？, *Sā, jikken o hajimeyou ka?*). After transforming, he says "The law of victory is set." (勝利の法則は決まった, *Shōri no hōsoku wa kimatta*).

## Powers and Abilities

* **Hazard Level 3 Physiology:** Sento underwent an experiment from Faust which injected him with a certain amount of Nebula Gas. However, instead of mutating into a Smash, the gas retained his body without side affects apart from memory loss (mostly inflicted by Blood Stalk). As result, his initial Hazard Level starts at Level 3, which allows subjects like him to utilize the Build Driver to transform into Kamen Rider Build.
* **Genius-Level Intellect:** Sento's most defining trait is his intelligence. He has an advanced knowledge of physics, and developed several of Build's accessories on his own.
	+ **Genius Physicist:** Sento has an advanced knowledge of physics, having finished a difficult physics test with perfect results. This proves a significant asset in battle, which Sento incorporates into his fighting technique.
	+ **Genius Engineer:** Sento has built the majority of Build's accessories, as well as all of Cross-Z's equipment, on his own.
	+ **Strategist:** Sento has shown him to be a capable strategist, being able to outwit even Blood Stalk on two occasions.
* **Fullbottle Augmentation:** By using a Fullbottle in his hand without transforming, Sento can gain abilities based on said Fullbottle's traits:
	+ **Rabbit:** Allows Sento to gain fast reflexes. First used to defeat Ryuga Banjou in a one-on-one fight.
	+ **Gorilla:** Allows Sento to perform fiery punches. First used to fight Ryuga Banjou.

### Weaknesses

* **Narcissism:** Sento has overwhelming confidence in his own skills, so he tends to be proud of his own achievements and look down on others (especially anyone who relies on his inventions), which contributes to his prideful personality. Sento often relies on his own skills to solve problems and never expects sudden assistance from others, so when it happens, he tends to either be surprised or turns them down. Also Sento can be easily caught off guard when he accomplishes anything or witnesses something unexpected and new which excites him, because of his reliance on his intellect. In this state, he is vulnerable to any surprise attacks.
* **Desperate Curiosity:** Sento can be easily attracted to anything that is mysterious and interesting and tends to do a total discovery for it, such as new innovations and anything that brings him closer to uncovering his past. This will continue until either he reaches a conclusion or someone forcibly stops him during progress.

## Forms

Sento sets two different Fullbottles into the Build Driver and turns the crank to transform into Kamen Rider Build. Kamen Rider Build, like Kamen Riders Double and OOO before him, can assume a variety of different forms, called **Trial Forms** (トライアルフォーム, *Toraiaru Fōmu*), using different combinations of Fullbottles. However, each one has a **Best Match** (ベストマッチ, *Besuto Matchi*) with another Fullbottle that creates an especially powerful form. Best Matches usually have unique names in comparison to other mismatched forms, and the caps of Fullbottles indicate what Fullbottle is its Best Match. The additional use of the Hazard Trigger upgrades a Best Match into a **Super Best Match** (スーパベストマッチ, *Supā Besuto Matchi*).

Build initiates a finishing attack by turning the Build Driver's Vortex Crank again. The finisher of all Trial Forms is called the **Vortex Attack** (ボルテックアタック, *Borutekku Atakku*), while the finisher of the Best Matches is called the **Vortex Finish** (ボルテックフィニッシュ, *Borutekku Finisshu*). The finisher of the Super Best Matches is called the **Hazard Finish** (ハザードフィニッシュ, *Hazādo Finisshu*).

* Standard

* Rabbit
* Gorilla
* Harinezumi

In any form that uses the Rabbit Fullbottle, Build is armed with the **Rabbit Foot Shoes** (ラビットフットシューズ, *Rabitto Futto Shūzu*) on his left leg for increased jumping, and can summon the **Drill Crusher**.

* Tank

**RabbitTank Form**

"*Rabbit! Tank! Best Match! Are you Ready? (Techno Rock music) Hagane no Moonsault! RabbitTank! Yeahhh!*"
―RabbitTank's transformation announcement[[src]]
**Rider Statistics**

* **Rider Height**: 196.0 cm
* **Rider Weight**: 99.0 kg

**Ability Perimeters**:

* **Punching Power**: 9.9 tons (right arm)/17.0 tons (left arm)
* **Kicking Power**: 23.7 tons (right leg)/17.8 tons (left leg)
* **Maximum Jump Height**: 55.0 m
* **Maximum Running Speed**: 100 m. per 2.9 sec.

**RabbitTank Form** (ラビットタンクフォーム, *Rabitto Tanku Fōmu*) is Build's red and blue primary and default Best Match form form accessed from the Rabbit and Tank Fullbottles, hence known as the **Moonsault of Steel** (鋼のムーンサルト, *Hagane no Mūnsaruto*). It is themed after a rabbit and a tank.

RabbitTank is considered to be the most well balanced; having a good amount of power and agility in all of his Ability Perimeters, thus making it Build's default form, despite it being capable of initiating transformation with any set of Build's Fullbottles. This is also Build's second fastest form.

In this Best Match form, Build is armed with the **Tank Roller Shoes** (タンクローラーシューズ, *Tanku Rōrā Shūzu*) on his right leg for kicking attacks, and can also act as a working tread to roll along on a flat foot.

This form's weapon is the Drill Crusher.

As a Best Match, this form has two finishers:

* Build Driver finisher:
	+ **Vortex Finish** (ボルテックフィニッシュ, *Borutekku Finisshu*): Build dives underground to send a white energy chart flying up to the surface with the dotted line securing the enemy before leaping back up, and delivering a kick whilst riding the chart's line. According to Blood Stalk, this finisher has a Hazard Level of 3.2, and then 3.7 when Build attacks him out of anger.
* Drill Crusher finisher:
	+ **Vortex Break** (ボルテックブレイク, *Borutekku Bureiku*):
		- **Blade:** Build channels the energy of a Fullbottle in his Drill Crusher and performs a powerful slash.
			* Organic:
				+ **Rabbit:** The Drill Spiral Blade spins such that it creates an energy whirlpool before Build performs a red energy slash.
				+ **Gorilla:** The Drill Spiral Blade cloaks itself in an energy projection that bears a striking resemblance to the Muscle Glove.
				+ **Ninjya:** Purple energy Drill Spiral Blades are projected and spin violently around the Drill Crusher.
			* Inorganic:
				+ **Rocket:** The Drill Crusher charges at the enemy and attacks like a rocket.
		- **Gun:** Build channels the energy of a Fullbottle in his Drill Crusher and performs a powerful blast.
			* **Harinezumi:** Build shoots white energy spikes at the enemy.

In any form that uses the Gorilla Fullbottle, Build is armed with the **Muscle Glove** (マッスルグローブ, *Massuru Gurōbu*) on his right arm for enhanced punching.

* Diamond

**GorillaMond Form**

"*Gorilla! Diamond! Best Match! Are you Ready? (Tropical Rock music) Kagayaki no Destroyer! GorillaMond! Yeahhh!*"
―GorillaMond's transformation announcement[[src]]
**Rider Statistics**

* **Rider Height**: 189.0 cm
* **Rider Weight**: 112.0 kg

**Ability Perimeters**:

* **Punching Power**: 25.9 tons (right arm)/15.8 tons (left arm)
* **Kicking Power**: 17.3 tons (right leg)/16.5 tons (left leg)
* **Maximum Jump Height**: 32.5 m
* **Maximum Running Speed**: 100 m. per 8.4 sec.

**GorillaMond Form** (ゴリラモンドフォーム, *Goriramondo Fōmu*) is Build's brown and cyan second Best Match form accessed from the Gorilla and Diamond Fullbottles, hence known as the **Shining Destroyer** (輝きのデストロヤー, *Kagayaki no Desutoroyā*). It is themed after a gorilla and a diamond.

In this Best Match form, Build is armed with the **BLD Prism Glove** (BLDプリズムグローブ, *BLD Purizumu Gurōbu*) on his left hand.

GorillaMond shows an increase in power, as the Punching Power of Build is significantly higher than in RabbitTank, albeit with a slightly decreased amount in its left arm, but it lacks Kicking Power and agility compared to RabbitTank. His left arm can convert inorganic objects, or even weakened enemies, into diamonds.

As a Best Match, this form's finisher is the **Vortex Finish** (ボルテックフィニッシュ, *Borutekku Finisshu*): This finisher has two variations:

* Build uses the BLD Prism Glove creates a gust full of diamonds and uses the Muscle Glove to punch them at the enemy. The diamond then creates a tornado that causes a human to separate from his/her Smash form, then Build punches the Smash inside the tornadoes, thereby defeating the Smash.
* Build stops an enemy's projectile attack in mid-air with the BLD Prism Glove, altering the projectiles' atomic structure into a diamond shield. He then punches the shield with the Muscle Glove, shattering it and sending the shards flying at the enemy at high speeds.

In any form that uses the Harinezumi Fullbottle, Build is armed with the **Spine Knuckle** (スパインナックル, *Supain Nakkuru*) on his right fist, allowing him to clobber foes with spikes that extend outwards when used. When first used after transforming, the spines notably appear to fly *in* from the surroundings *to* the Spine Knuckle, only extending from it on subsequent attacks.

* KR Drive
* Tank

**TypeSpeedHedgehog Form**

"*Harinezumi! Drive! Best Match! Are you Ready? (Techno Pop music) Speed Racer! SonicHedgehog! Yeahhh!*"
―SonicHedgehog's transformation announcement[src]
**Rider Statistics**

* **Rider Height**: 190.0 cm
* **Rider Weight**: 103.7 kg

**Ability Perimeters**:

* **Punching Power**: 13.7 tons (right arm)/11.9 tons (left arm)
* **Kicking Power**: 14.7 tons (right leg)/14.0 tons (left leg)
* **Maximum Jump Height**: 36.5 m
* **Maximum Running Speed**: 100 m. per 6.4 sec.

**SonicHedgehog Form** (ソニックヘッジホッグフォーム, *Sonikku Harinezumi fōmu*) is Build's white and blue-colored Best Match form accessed from the Harinezumi and Kamen Rider Drive Fullbottles. It is themed after a hedgehog and Type Speed.

As a Best Match, this form's finisher is the **Vortex Finish** (ボルテックフィニッシュ, *Borutekku Finisshu*): Build extends the Multi Deluge Gun and uses it to stab the enemy, then fills them up with water and surrounds them with a white energy chart before jumping up such that he's perpendicular with the ground, then dropping down, and punching the enemy with the Spine Knuckle.

**HarinezumiTank Form**

"*Harinezumi! Tank! Are you Ready?*"
―HarinezumiTank's transformation announcement[[src]]
**Rider Statistics**

* **Rider Height**: 194.0 cm
* **Rider Weight**: 102.7 kg

**Ability Perimeters**:

* **Punching Power**: 11.0 tons (right arm)/13.6 tons (left arm)
* **Kicking Power**: 19.0 tons (right leg)/11.2 tons (left leg)
* **Maximum Jump Height**: 28.4 m
* **Maximum Running Speed**: 100 m. per 7.0 sec.

**HarinezumiTank Form** (ハリネズミタンクフォーム, *Harinezumi Tanku Fōmu*) is Build's white and blue Trial Form accessed through the Harinezumi and Tank Fullbottles, themed after a hedgehog and a tank.

Compared to RabbitTank, this Trial Form has a stronger amount of Punching Power in its right arm, while being weaker in the left. The rest of the Ability Perimeters are overall much worse in comparison.

In this Trial Form, Build is armed with the **Tank Roller Shoes** (タンクローラーシューズ, *Tanku Rōrā Shūzu*) on his right leg for kicking attacks, and can also act as a working tread to roll along on a flat foot.

As a mismatched form, this form's finisher is the **Vortex Attack** (ボルテックアタック, *Borutekku Atakku*).
## Equipment

### Devices

* Build Driver - Transformation device.
* Fullbottles - Transformation trinkets.
* Fullbottle Holder - Carrier strap for Build's Fullbottles
* Build Phone - Build's personal smartphone that can transform into the Machine Builder.

### Weapons

* Handheld weapons
	+ Drill Crusher - Build's personal drill-like weapon
	+ Rabbit Foot Shoes - Build's rabbit-like spring shoe accessed by any form that uses the Rabbit Fullbottle and in RabbitTank Sparkling Form.
	+ Tank Roller Shoes - Build's tank-like tread shoe accessed by any form that uses the Tank Fullbottle and in RabbitTank Sparkling Form.
	+ Muscle Glove - Build's gorilla-like tekko accessed by any form that uses the Gorilla Fullbottle.
	+ Spine Knuckle - Build's hedgehog-like tekko accessed by any form that uses the Harinezumi Fullbottle.
	+ Build Pad Shield - Build's smartphone-like shield accessed by any form using the Smapho Fullbottle.

### Vehicles

* Machine Builder - Build's personal Rider Machine that is transformed from the Build Phone.

## Rider Gashat

**Kamen Rider Build** (仮面ライダービルドガシャット, *Kamen Raidā Birudo Gashatto*)

## Relationships

* Allies
	+ nascita
		- Misora Isurugi: **TBA**
		- Ryuga Banjou: **TBA**
		- Sawa Takigawa: **TBA**
* Enemies:
	+ Gentoku Himuro/Night Rogue: **TBA**
	+ Soichi Isurugi/Blood Stalk: **TBA**
* Others:
	+ Tatsuya Kishida: **TBA**
	+ Taro Satou: **TBA**
	+ Takumi Katsuragi: **TBA**

## Behind the Scenes

### Etymology

According to Soichi Isurugi, the kanji used to spell Sento's first name, Sento (戦兎, *Sento*), is composed of the first kanji for *tank* (戦車, ***Sen**sha*) and the kanji for *rabbit* (兎, ***To***); this is referring to Build's primary form, RabbitTank. The last name was provided by the name of the barber shop Soichi had been headed out to by the time he "found" Sento.