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Icon-fourze.png This article is about a transformation device in Kamen Rider Fourze.

"3, 2, 1! (Techno space music)"
―Transformation announcement[src]

"(Astroswitch name)!"
―Switch insertion announcement announcement[src]

"(Astroswitch name) On!"
―Switch activation announcement[src]

"(1-4 activated Astroswitch names) Limit Break!"
―Finisher announcement[src]

The Transformation Belt Fourze Driver (変身ベルト フォーゼドライバー, Henshin Beruto Fōze Doraibā) was Kamen Rider Fourze's transformation belt that was given to Gentaro by Kengo Utahoshi.

It was invented by Kengo's father Rokuro Utahoshi while researching Core Switch. The original purpose of this driver was for space travel by utilizing Astroswitches until the appearances of Zodiarts.


The Fourze Driver consists of the following parts:

  • Status Monitor (ステイタスモニター, Suteitasu Monitā) - The main central screen in the Fourze Driver's middle. As each Astroswitch is activated in their Switch Sockets, a graphic representing the switch's respective limb turns on.
  • Umbilical Injector (アンビリカルインジェクター, Anbirikaru Injekutā) - A piece of equipment installed in the rear part of the Fourze Driver's Pit Control Base that touches Fourze's abdomen. It directly supplies energy to Fourze's suit.
  • ASX-4000 (ASX-4000(エーエスエックスフォーティーハンドレッド), ASX - 4000 (Ē Esu Ekkusu Fōtī Handoreddo)) - Pronounced as 'ASX Forty-Hundered', it is the Fourze Driver's main computer installed within the motherboard unit below the Status Monitor. Four core chips with high stability, called Frontier C3 (「Frontier C3」) act as CPUs, operating at 2.0GHz each. It also contains the speaker in which transformation and attack annoncements are spoken through.
  • Pit Control Base (ピットコントロールベース, Pitto Kontorōru Bēsu) - The Fourze Driver's exterior. It is a control interface that allows the user to insert Astroswitches into it.
  • Switch Sockets (スイッチソケット, Suitchi Soketto) - Sockets embedded into the Fourze Driver that Astroswitches are plugged into. It prevents Cosmic Energy from leaking out when using the Astroswitches. Different shaped Switch Sockets prevent Astroswitches without the corresponding shape from being plugged in.
  • Transwitches (トランスイッチ, Toransuichi) - The Fourze Driver's red push switches located below the Switch Sockets. Pressing it forms a circuit between the Astroswitches and the Fourze Driver, allowing Cosmic Energy to flow through, enabling transformation and Module summoning. This is why all four Switch Sockets must have Astroswitches within them to transform.
  • Capture Handle (キャプチャーハンドル, Kyapuchā Handoru) - The Fourze Driver's main handle on the right side of the belt.
  • Enter Lever (エンターレバー, Entā Rebā) - The Fourze Driver's main lever. Pushing it will draw out the Astroswitch's energy, enabling transformation.
  • Power Harness (パワーハーネス, Pawā Hānesu) - The Fourze Driver's strap. It automatically adjuts itself based on the wearer's waist size.
  • Release Buttons (リリースボタン, Rirīsu Botan) - Small grey buttons on either side of the Fourze Driver located above the Circle and Square Switch Sockets. Pressing them will release the Fourze Driver from the wearer's waist.
  • Heat Sink Plates (ヒートシンクプレート, Hīto Shinku Purēto) - Plate sections with 5 holes in each attached to the Power Harness. They dissipate heat generated by the ASX-4000.



To transform into Fourze, the user must first insert four Astroswitches into the Switch Sockets (スイッチソケット, Suitchi Soketto) if they weren't there already, and flips the red Transwitches (トランスイッチ, Toransuichi) down, turning on the Status Monitor (ステイタスモニター, Suteitasu Monitā) with each thrown Transwitch, to begin the countdown. Afterwards, the user pushes the Enter Lever (エンターレバー, Entā Rebā) on the side of the belt and raises his right arm in the air.


Main article: Limit Break

By switching on a correspondent Astroswitch, or a combination of Astroswitches, before pushing the Enter Lever again, Fourze can perform a Limit Break (リミットブレイク, Rimitto Bureiku) finishing attack.

While executing a Double Limit Break is possible, it was risky as it would completely drain an Astroswitch's power for a while, rendering one of them useless until they were completely recharged.



The Fourze Driver was invented by the father of Kengo Utahoshi, based on his research in Cosmic Energy. The Circle, Cross, Triangle, and Square Basement designs were based off of the pillars in Kyoto, where Utahoshi and his team researched the Hole over the city.

Later history

The Fourze Driver destroyed

5 years later, Gentaro used the Fourze Driver once again to fight alongside Riders old and new against Foundation X. Kamen Rider Heisei Generations FINAL: Build & Ex-Aid with Legend Riders Not long after, Gentaro, in a last attempt to persuade Sanagiman to redeem himself, ultimately destroyed the belt by throwing it into a vat of molten steel at a factory as a sign of truce, his act was understood and accepted by Kengo.

He later borrows the Fourze Driver from his present day self to fight alongside Wizard. After the future Gentaro returns to his own time, Haruto gives the Driver back to the Gentaro of the present. Afterwards, as the rest of Kamen Rider Club lamented its destruction, Kengo was certain that, as the Fourze Driver was Gentaro's friend, it would always return when it was truly needed. Kamen Rider × Kamen Rider Wizard & Fourze: Movie War Ultimatum


  • Fourze can access his other States without changing into Basestates. It was done by activating the switch before transforming. It was first used in the first fight against the Sagittarius Zodiarts by transforming straight into Cosmicstates, in order to protect the critically injured Tachibana.
  • The Fourze Driver is also donned by Mitsuki Endo of Kamen Rider Girls, who represents Fourze in the group.
  • Unless future events change the circumstances, this is the first time in the franchise that a main Rider's Belt has been permanently destroyed willingly by its user.

External Link


Icon-fourze.png Kamen Rider Fourze
Kamen Riders
Gentaro Kisaragi - Ryusei Sakuta - Nadeshiko Misaki - Kamen Rider Ikaros - Rider Hunter Boot
Fourze Driver - Meteor Driver- Nadeshiko Driver - Astroswitches - Astroswitch Case - Billy the Rod - Hee-Hackgun - NS-MagPhone - Meteor Galaxy - Barizun Sword - Meteor Storm Shaft - Machine Massigler - Machine Meteorstar - Powerdizer
Kamen Rider Club
Initial Members
Yuki Jojima - Kengo Utahoshi - Miu Kazashiro - Shun Daimonji - Tomoko Nozama - JK - Chuta Ohsugi - Ran Kuroki - Haru Kusao
5 Years After
Saburo Kazeta - Rumi Komaki - Daita Kondou - Chikao Nezu - Miyoko Ohki
Ishinomori Characters
Inazuman - XVII - Skydain - Groundain - Black Knight - Inga Blink
The Horoscopes: Sagittarius - Virgo - Leo - Libra - Scorpio - Cancer - Aries - Capricorn - Aquarius - Taurus - Gemini - Pisces

Zodiarts: Orion - Chameleon - Unicorn - Hound - Altar - Pyxis - Perseus - Lynx - Dragon - Pegasus - Cygnus - Coma - Musca - Hercules - Lepus

Stardust Ninja Dustards
Foundation X
Lem Kannagi - Katal - Solaris - Chancellor Kiima - Suddendath Beta
Xatan - Eel - Gahra