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Icon-build.png This article is about a/an temporary villain in Kamen Rider Build.

Masahiro Nabeshima (鍋島 正弘 Nabeshima Masahiro) is a prison guard working for Faust. Later he became one of the victims of Faust's experiments who got turned into the Mirage Smash (ミラージスマッシュ Mirāji Sumasshu) and later the second Square Smash (スクエアスマッシュ Sukuea Sumasshu). His Smash essences were used as the basis for the Ninjya (Mirage Smash) and Comic (Square Smash) Fullbottles.

Character History

Little is known about Nabeshima aside from his role in Ryuga Banjo's life. At an unknown point in time, Faust forced Nabeshima into joining them, threatening to kill his wife and daughter if he refused.

On the orders of Blood Stalk, he approached Kasumi Ogura, Ryuga's fiancée, and had her direct Ryuga to Takumi Katsuragi in exchange for helping Ryuga make a comeback as a fighter. When Ryuga arrived to meet Katsuragi, he was framed for the latter's murder and imprisoned, where Nabeshima sedated him and brought him to be experimented on by Faust. That One with the Best Match

Following his escape, Ryuga managed to contact Nabeshima, calling him to demand a confession. Nabeshima revealed to Ryuga that the organization that experimented on him, Sento, and the Smash was called Faust, and that they were holding his family in Seito, saying he would testify against Faust if Ryuga rescued them. However, this information was delivered on Night Rogue's order to lure Ryuga to Seito. Nabeshima demanded his family be freed in exchange for playing along; instead, his reward for his service was being turned into the Mirage Smash. He attacked a group of Touto Guardians and Sento, fighting Build RabbitTank by duplicating himself. After Build switched to HawkGatling and defeated him and all his duplicates, his Smash essence was removed into a blank Full Bottle. However, he was taken away by Blood Stalk after being recognized by Sento. Borderline of Justice

Nabeshima was injected with Nebula Gas again, transforming into the Square Smash. He was set upon a park, coming to blows with Build once again. After fighting for some time, Blood Stalk fires upon him with his Steam Rifle, causing him to grow in size. Build proceeds to defeat him with the Full Bullet finisher, and upon having his Smash essence extracted returns to normal once again.

Some time later he wakes up in nascita's basement lab. However, the second Smash transformation has robbed him of all his memories, unable to even recognize his wife and daughter. Shortly after the reunion he goes over to the panel with the Fullbottles plugged in, suddenly remembering that Faust had similar bottles as well. The Testimony Will Be Zero

Sometime after Faust's supposed dismantling, Nabeshima managed to recover some of his memories, calling Sento to tell him who told him to pin Takumi Katsuragi's murder on Ryuga: Blood Stalk, also known as Soichi Isurugi. Theory of Conspiracy Who Takes Off The Veil?

Sometime before the proxy fight between Touto and Seito to determine the outcome of the war over Pandora's Box, Nabeshima's family was kidnapped by Namba Heavy Industries, and were used by Juzaburo Namba to pressure Sawa Takigawa into stealing data on Build's new power up item. However, their plan would end in failure as Sento gave Sawa half the data in order to buy time for Kazumi Sawatari to find and rescue Nabeshima's family.


Mirage Smash

  • Height: 207.2 cm.
  • Weight: 112.2 kg.
Powers and Abilities
  • Super Speed: The Mirage Smash can move at blinding speeds to dodge attacks and attack its opponent.
  • Duplication: The Mirage Smash can split itself into an army of independently-functioning copies to overwhelm an opponent; defeating the prime Smash will defeat all copies.

Appearances: Build Episode 3

Incomplete Square Smash

An incomplete form of the Square Smash with a small cube head over a collar-mounted half block. Nabeshima became this form upon his second Smash conversion.

Appearances: Build Episode 4

Square Smash

  • Height: 203.5 cm.
  • Weight: 134.7 kg.

The complete Square Smash, after the top half of its larger block head appears, covering its initial cube head. Nabeshima became this form before encountering Sento.

Powers and Abilities
  • Block Creation: The Square Smash can cut blocks from any material with its knife right arms. It can throw these blocks to attack opponents or raise columns of them for defense.
  • Enhanced Jump: The Square Smash can jump long and high distances.

Appearances: Build Episode 4

Square Smash giant.png
A giant version of the normal Square Smash form, Nabeshima became this form after being exposed to another dose of Nebula Gas while already a Smash.

Powers and Abilities
  • Enhanced Strength: After being enlarged by Blood Stalk, his strength is increased, although he loses his agility.

Appearances: Build Episode 4

Smash Bottle

Smash Bottle
(Mirage Smash)

This Smash Bottle contains the essence of the Mirage Smash.

Smash Bottle
(Square Smash)

This Smash Bottle contains the essence of the Square Smash.

Behind the Scenes


Masahiro Nabeshima was portrayed by Ichi Oomiya (市オオミヤ Ichi Ōmiya). In both of his Smash forms, he was portrayed by suit actor Satoshi Fujita (藤田 慧 Fujita Satoshi).

Concept Art

Mirage Smash and Square Smash were designed by Tamotsu Shinohara (篠原 保 Shinohara Tamotsu).


  • The incomplete Square Smash's suit is later reused as Fang Smash.



Icon-build.png Kamen Rider Build
Kamen Riders
Sento Kiryu (Takumi Katsuragi) - Ryuga Banjo - Kazumi Sawatari - Gentoku Himuro - Evolto - Nariaki Utsumi - Shinobu Katsuragi
Movie-exclusive: Kengo Ino - Killbus - Keiji Uraga
Drivers/Transformation Gear
Build Driver - Transteam Gun - Nebulasteam Gun - Sclash Driver - Evol-Driver
Transformation Devices
Fullbottles - (Great) Cross-Z Dragon - Sclashjellies - Hazard Trigger - Cross-Z Magma Knuckle - Evol-Trigger - Grease Blizzard Knuckle - Killbuspider - Grease Perfect Kingdom
Drill Crusher - Hawk Gatlinger - 4Koma Ninpoutou - Kaizoku Hassyar - Fullbottle Buster - Steam Blade - Beat Closer - Twin Breaker - Muscle Glove - Solstall Wings - Giant Scratcher - Space Ride Arm - Spine Knuckle - Long Range Cleaner - Trash Converter - Gold Lio Gauntlet - Multi Deluge Gun
Pandora Box - Halfbodies - Fullbottle Holder - Build Phone
Vortex Finish - Hazard Level - Project Build - Sky Wall - Nebula Gas
nascita: Misora Isurugi - Soichi Isurugi - Sawa Takigawa - Kazumi Sawatari - Gentoku Himuro
Kamen Riders: Eiji Hino - Gentaro Kisaragi - Kouta Kazuraba - Takeru Tenkuji - Emu Hojo - Hiiro Kagami - Taiga Hanaya - Kiriya Kujo - Kuroto Dan - Parado - Sougo Tokiwa - Geiz Myokoin - Tsukuyomi
Prime Ministers: Taizan Himuro (Touto) - Yoshiko Tajimi (Hokuto) - Masakuni Mido (Seito)
Namba Heavy Industries Ltd.: Juzaburo Namba - Nariaki Utsumi - Haruhiko Wanibuchi - Guardian
Hell Bro's: Fu Washio - Rai Washio - Yoshikazu Takahashi - Norio Matsui
Aliens: Vernage
Gentoku Himuro - Evolto - Nariaki Utsumi - Takumi Katsuragi - Shingo Kuwata - Eita Kawai - Yoshikazu Takahashi - Norio Matsui
Normal Smash: Fang Smash - Needle Smash - Strong Smash - Burn Smash - Flying Smash - Mirage Smash - Square Smash - Press Smash - Ice Smash - Stretch Smash
Empowered Smash: Strong Smash Hazard - Press Smash Hazard - Stretch Smash Hazard - Flying Smash Hazard
Hard/Hazard Smash: Castle Hard/Hazard Smash - Stag Hard/Hazard Smash - Owl Hard/Hazard Smash
Clone Smash: Press Clone Smash - Stretch Clone Smash - Strong Clone Smash - Flying Clone Smash
Lost Smash: Owl Lost Smash - Stag Lost Smash - Castle Lost Smash - CD Lost Smash - Scissors Lost Smash - Zebra Lost Smash
Foundation X
Kaisers: Kaisei Mogami (World of Build, World of Ex-Aid) - Nebula Bugster
Blood Tribe
Kengo Ino - Ryoka Saiga - Mitsuomi Gobara - Evolto - Killbus - Akaba (imitation) - Aoba (imitation) - Kiba (imitation) - Remocon Bro's (imitation) - Engine Bro's (imitation)
Down Fall
Keiji Uraga - Simon Marcus (Phantom Crusher)