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

Kiba (黄羽), born Syoukichi Mihara (三原 昌吉 Mihara Shōkichi), is one of the boys who hailed from Hokuto, part of the Hokuto Sanbagarasu led by Kazumi Sawatari. He was able to change into the Owl Hard Smash (オウルハードスマッシュ Ōru Hādo Sumasshu)[1] using the Fukurou Fullbottle. After being administered the Hazard Trigger, he became Owl Hazard Smash (オウルハザードスマッシュ Ōru Hāzado Sumasshu)


Becoming Kiba

Syoukichi was originally a farm worker in Hokuto, employed by Kazumi Sawatari. After the Sky Wall Disaster, Hokuto's farm land was rendered unsuitable for crops. Sawatari spent all of his savings to continue providing for his employees and their families, and volunteered himself for Faust's experiments when his funds were depleted. Feeling indebted to Sawatari, Mihara volunteered himself as well, becoming a Hard Smash in the process, codenamed Kiba.

Invasion of Touto

When Hokuto Prime Minister Yoshiko Tajimi declared war on Touto, Kiba was part of the advance guard with Aoba and Akaba. Watching a live stream of lesser Smash being defeated by Kamen Rider Build, Kiba noted their limitations. He chided Akaba's use of his Smash power to attack the city prematurely, warning him not to cross the boss. The Weaponry Hero

Kiba and the others later tracked down Sento Kiryu and Ryuga Banjo, and transformed into their Hard Smash forms. After successfully knocking them out of their transformations, Akaba demanded that they hand over their Fullbottles, prompting Aoba and Kiba to argue with him over who should get said Fullbottles. By the time they had pulled themselves together, Sento and Ryuga had absconded.

Later, they found Sento consoling Misora Isurugi as she lamented her role in allowing evil to wage war, and told Sento to hand over his Fullbottles. This time, Sento gave them a challenge with a determination he gained from Misora, using RabbitTank Sparkling Form. However, Akaba, Aoba, and Kiba still quickly gained the upper hand, until Ryuga appeared with the Sclash Driver and transformed into Kamen Rider Cross-Z Charge. Ryuga and Sento easily defeated them, causing them to drop the Phoenix, Robot, Wolf, Smapho, Kuma, and Televi Fullbottles. Kazumi Sawatari arrived shortly after to challenge Sento and Ryuga. Rider Wars Start

Alongside Aoba and Akaba, Kiba interrupted a fight between Grease and Cross-Z Charge, only for Kazumi to state that they had broken the rules of engagement and relinquish the Kuma and Televi Fullbottles to Ryuga as his penance. Soon after, the Hokuto Sanbagarasu received dog tags from Kazumi which had finally accepted from Massugu Ubukata, whom crafted them out of respect; befitting the Owl Hard Smash, Kiba's tag was colored yellow. Kamen Rider Build: Birth! KumaTelevi!! VS Kamen Rider Grease!


"Idiot! What were you thinking?!"
"If I didn't...you wouldn't run..."
"I knew...you didn't lose your memories...You're such a bad liar!"
"Shut up!"
"Boss...I'll be there watching over you with Aoba.
―Kiba's final words to Kazumi.[src]

After Sento won the proxy fight to settle the war between Touto and Hokuto, Kiba, Akaba and Kazumi learned of Seito's invasion of Hokuto and from Blood Stalk that Seito forces have invaded Sawatari's farm, taking their friends and family hostage. Angered, Kiba secretly headed back to Hokuto and engaged the Seito Guardians holding his friends hostage. As Owl Hazard Smash he destroyed all of them, but was approached by the Washio brothers who utilized the Nebulasteam Gun and transformed into Engine Bro's and Remocon Bro's. Both brothers easily defeated Kiba, with Engine Bro's pinning Kiba down and demanding Kazumi, whom was watching a live broadcast with Sento, Ryuga, Akaba and Touto's Prime Minister Taizan, to join Seito. As they waited for Kazumi's response, the Washio brothers beat up and chained Kiba, nearly to death. When Kazumi and Akaba arrived, they turned into Kamen Rider Grease and the Castle Hazard Smash. While Grease takes on the Kaisers, Akaba freed Kiba and destroyed the Guardians, allowing their friends and family to escape. Overwhelming Grease, the Washio Brothers turned their attention to Kiba with Remocon Bro's firing the Nebulasteam Gun at him, but Akaba shielded him until the force of the blast knocked him aside. Seeing Kiba now vulnerable, Grease ran to intercept more gunfire, taking them from behind. Fearing the worst, Grease used the Helicopter bottle to use a Discharge Crush, forming a three-bladed helicopter rotor to get himself, Kiba and Akaba out of the farm and proceeded to the Sky Road back to Touto. However, the Washio Brothers pursued them, blasting Grease with three shots from the Nebulasteam Rifle to force them out of the sky. Grease, Akaba and Kiba landed heard near a waterfall, forcing Grease out of his tranformation. Kiba calls to him, stating he's done for as Kazumi noticed his body begins to disintegrate slowly. Kazumi struggled to reach Kiba until Akaba spotted the Washio brothers approaching them. Kiba tells Kazumi to run, but he knows he won't as Akaba attempted to fight the brothers off, but Engine Bro's knocked him aside and placed his Gear Engine in the Nebulasteam Rilfe, allowing Remocon Bro's to perform and Elec Steam Funky Shot. Spotting the rifle pointed at Kazumi, Kiba turned into the Owl Hazard Smash and shielded Kazumi, taking the finisher head on. Kiba fell down before turning back into his human form, his disintegration speeding up as Kazumi moves to his side. Kazumi insulted him for doing that, and Kiba stated he did it because Kazumi wouldn't run. To Kiba's surprise, Kazumi referred to him by his birth name, realizing Kazumi never lost his memories. As Kiba ripped off his dog tag with his name and placed it in Kazumi's name, as Aoba did before his death, Kiba told Kazumi he'll be watching over him beside Aoba before dying. His body completely disintegrated in a yellow smoke. The Phantom of the West


In respect for Kiba and Aoba, Sento left a bunch of yellow and blue flowers at the sight of the latter's death in Touto, which Stalk took as Sento shouldering their deaths. Soon after, Grease arrived to save Sento from going berserk after using the Hazard Trigger in his fight with Stalk, claiming it was thanks for the flowers. A Man Called Rogue

Akaba proposed to Kazumi that Kiba and Aoba's dog tags be buried at the Sky Road passage between Touto and Hokuto. Before they could tend to this, however, Akaba was confronted by Kamen Rider Rogue while guarding the Pandora Box and, despite calling on the power of his late teammates, was killed in action, leaving his and their dog tags to Kazumi. The Idol Awakens

Kazumi crafted a grave for the Sanbagarasu at the Sky Road. However, he held onto their dog tags as he participated in the Proxy Battle against Seito where, despite being outmatched by Engine Bro's, he was ultimately motivated to overcome his opponent by looking back to his late comrades. The Treacherous Deathmatch Kazumi would continue to fight to ensure the well-being of the late Sanbagarasu' respective families. The Counterattack Hero

New World

New Akaba, New Aoba and New Kiba.jpg
Kiba Grease.png


Kiba was the most childish of the Hokuto Sanbagarasu, speaking in a goofy manner and making whimsical observations. He was often seen squatting. Apparently, he also possessed a keen sense of smell.

After Aoba's demise on the hand of Build, Kiba becomes hot-headed and bitter. However, he didn't outwardly expressed his anger like Akaba.

Kiba was the one who notices that Kazumi is a really bad liar, nevertheless he still fought for his boss' sake.


Owl Hard Smash

Owl Hard Smash

  • Height: 203 cm.
  • Weight: 115 kg.

Kiba transforms into the Owl Hard Smash (オウルハードスマッシュ Ōru Hādo Sumasshu) using the Fukurou Fullbottle.


  • The Owl Hard Smash has the ability to fly.
  • The Owl Hard Smash is armed with the two Forest Seeker (フォレストシーカー Foresuto Shīkā) drones on its gauntlets.

Appearances: Build Episode 17-19

Owl Hazard Smash

Owl Hazard Smash

  • Height: 203 cm.
  • Weight: 115 kg.

After being administered with the Hazard Trigger's energy, Kiba can now transform into the Owl Hazard Smash (オウルハザードスマッシュ Ōru Hāzado Sumasshu) with the Fukurou Fullbottle.


  • The Owl Hazard Smash has the ability to fly.
  • The Owl Hazard Smash can launch yellow energy orbs from the Forest Seeker (フォレストシーカー Foresuto Shīkā) drones on its gauntlets.

Appearances: Build Episodes 19-23

Owl Lost Smash

KRBu-Owl Lost Smash.png

  • Height: 203 cm.
  • Weight: 115 kg.

The New World counterpart of Kiba transforms into the Owl Lost Smash (オウルロストスマッシュ Ōru Rosuto Sumasshu) using the Fukurou Lost Fullbottle.

This form is exclusive to Kamen Rider Build NEW WORLD: Kamen Rider Grease


Behind the Scenes


Kiba is portrayed by Takuya Yoshimura (吉村卓也 Yoshimura Takuya), who was rumored to portray Kazumi Sawatari before his actor was revealed. As Owl Hard Smash, his suit actor is Hajime Kanzaki (神埼元 Kanzaki Hajime).


Kiba's name translates to "yellow wings", sharing a color theme with Aoba (青羽 lit. "blue wings") and Akaba (赤羽 lit. "red wings"). Incidentally, his name is also phonetically identical to the word fang ( Kiba)".



See Also


Sento Kiryu (Takumi Katsuragi) - Ryuga Banjo - Kazumi Sawatari - Gentoku Himuro - Evolto - Nariaki Utsumi - Shinobu Katsuragi
Movie-exclusive: 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
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
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 Build, World of Ex-Aid)
Kengo Ino - Ryoka Saiga - Mitsuomi Gobara - Evolto - Killbus
Keiji Uraga - Simon Marcus (Phantom Crusher)
Community content is available under CC-BY-SA unless otherwise noted.