This article is about a/an temporary villain in Kamen Rider Build.

Kyoichi Shimizu (志水恭一 Shimizu Kyōichi) was one of the victims of Faust's experiments who was turned into the Strong Smash (ストロングスマッシュ Sutorongu Sumasshu). His Smash essence was used as the basis for the Gorilla Fullbottle. He later uses the Kuwagata Fullbottle to become the Stag Lost Smash (スタッグロストスマッシュ Sutaggu Rosuto Sumasshu)

Character History

Shimizu was present during Ryuga Banjo's escape from Faust's experiment, recognized by his signature dragon-shaped ear decoration, later being turned into the Strong Smash.

The Strong Smash appeared and attacked Sento Kiryu and Ryuga, grabbing Ryuga and trying to take him away, presumably back to the facility. Ryuga fought back without success, but Sento transformed into Kamen Rider Build RabbitTank and fought it. He briefly took HarinezumiTank before returning to RabbitTank and defeating the Smash with Vortech Finish, extracting the Smash essence with a blank Fullbottle. Questioned by Ryuga, Shimizu claimed to remember nothing, escaping into some tall grass as a squad of Touto Guardians arrived. That One with the Best Match

The Bottle was later purified into the Gorilla Fullbottle. The Innocent Runaway

Later, presumably under Evolto command, Shimizu encounter Sento and by using Kuwagata Lost Fullbottle, he becomes Kuwagata Lost Smash and attacks Sento. Sento later cancels his transformation using Build Genius form. However, just before Shimizu leaks more info about Katsuragi Shinobu, Evolto kills him by injecting Shimizu with a lethal dose of poison that disintegrates him.


Strong Smash
KRBu-Strong Smash

Strong Smash

  • Height: 204 cm.
  • Weight: 142 kg.

The first Smash form Shimizu took after being exposed to Nebula Gas by Faust.

Powers and Abilities
  • The Strong Smash wields vast physical strength, seen when it knocked a car several meters away with one punch.
  • The Strong Smash can also jump very high into the air.

Appearances: Build Episode 1

Stag Lost Smash
KRBu-Stag Lost Smash

Stag Lost Smash

  • Height: 205.2 cm.
  • Weight: 124.4 kg.

Shimizu transforms into the Stag Lost Smash by using the Kuwagata Lost Fullbottle and absorbing two Clone Smash

Powers and Abilities

  • The Stag Lost Smash is armed with the pair of sword-like Rapture Scissors (ラプチャーシザース Rapuchā Shizāsu).
  • The Stag Lost Smash can move at super speed.

Appearances: Build Episode 41

Behind the scenes


Shimizu was portrayed by Shohei Yamazaki (山﨑将平 Yamazaki Shohei). As both the Strong Smash and Stag Lost Smash, he was portrayed by suit actor Hajime Kanzaki (神前 元 Kanzaki Hajime).


Sento Kiryu (Takumi Katsuragi) - Ryuga Banjo - Kazumi Sawatari - Gentoku Himuro - Evolto - Nariaki Utsumi - Shinobu Katsuragi - Kengo Ino - Killbus - Keiji Uraga
Transformation Gear
Fullbottles - Build Driver - Transteam Gun - (Great) Cross-Z Dragon - Sclashjellies - Sclash Driver - Hazard Trigger - Nebulasteam Gun - Cross-Z Magma Knuckle - Evol-Driver - 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
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
Downfall: Keiji Uraga - Simon Marcus
Gentoku Himuro - Evolto - Nariaki Utsumi - Takumi Katsuragi - Shingo Kuwata - Eita Kawai - Yoshikazu Takahashi - Norio Matsui
Touto: Needle Smash - Strong Smash - Burn Smash - Flying Smash - Mirage Smash - Square Smash - Press Smash - Ice Smash - Stretch Smash
Hokuto: Castle Hard Smash - Stag Hard Smash - Owl Hard Smash
Kaiser: Kaisei Mogami (World of Ex-Aid)
Kengo Ino - Ryoka Saiga - Mitsuomi Gobara - Evolto - Killbus
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