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

Masakuni Mido (御堂 正邦 Midō Masakuni) was the Prime Minister of Seito, before being murdered by Evolto who later impersonated him, following Juzaburo Namba.

Character History

Mido was holographically present in Touto at a monthly scheduled meeting with Prime Ministers Taizan Himuro and Yoshiko Tajimi. They discussed their economic progress, and Mido along with Tajimi declined to make any unified movements when Himuro suggested so. Borderline of Justice In a later meeting in Touto, as Tajimi berated Himuro over the presence of the Kamen Rider and Smash in Hokuto, Mido pointed out that they only seem to appear in Touto, but both foreign ministers were assured by Gentoku Himuro that Touto would handle the issue and accused of trying to scapegoat Touto. Memory Starts To Talk

When the Prime Ministers met in Touto to examine the Pandora Box, an energy shield locked them in with it, activated by Faust with intel from Gentoku Himuro. Soon after, they were menaced by Blood Stalk before he took the Pandora Box. After regrouping later, Mido and Tajimi were quick to demand explanations from Himuro, stressing him out to the point of a heart attack. Technology of Destruction

Mido watched the broadcast of a proxy battle held to decide the conflict between Hokuto and Touto, respectively represented by Kamen Riders Build and Grease. Knowing that the bulk of Hokuto's forces were engaged in the invasion of Touto, Mido had secretly arranged for Seito's army of Guardians led by their own Kamen Rider to seize the nation of Hokuto. His counterpart Yoshiko Tajimi, having been sold out by Blood Stalk, only learnt this when the proxy battle ended with defeat for Hokuto, and was taken into custody on Mido's orders. Victory of Tears

With the personal backing of CEO Juzaburo Namba of Nanba Heavy Industries, Mido followed up the subjugation of Hokuto by declaring war on Touto. Having been provided with the new Kaisers, Engine and Remocon Bro's, Mido presented Seito's fighting prowess in a message broadcast to the Touto government, presenting Seito's Guardians and Kaisers at the Sawatari Farm. Mido gave his personal thanks to Nariaki Utsumi, who was responsible for updating the Kaiser System originally developed by Kaisei Mogami. The Phantom of the West

Having had Touto's government office bugged, Mido learnt from a conversation between Taizan Himuro and Sento Kiryu that, in light of Gentoku's new allegiance to Seito as Kamen Rider Rogue, they were planning to move the Pandora Box to a secure location. Before this could happen, Mido sent Gentoku to claim the Pandora Box for Seito. A Man Called Rogue

Mido died in his office.

After Rogue was defeated by Build, He is murdered by Blood Stalk, and being replaced by the president of Namba Heavy Industries Ltd. as his new identity. The Genius Arrives With a Tank


In the guise of Masakuni Mido, Namba launched a new invasion of Touto. As the Proxy Battle had not been made available for viewing by the general populace of Japan, "Mido" made the claim that Seito had actually prevailed, and that Touto was refusing to abide by the terms agreed. The Opening Bell Rings

Gentoku is aware of Namba masquerading as Mido, so he informs Sento that "Mido" was actually Namba in disguise during their fight.The Truth of the Pandora Box Surging Magma!

"Masakuni Mido" made his final appearance in a live address broadcast nationwide from Pandora Tower. Recounting the events of the Sky Wall Disaster and the resulting Japanese Civil War culminating in the reunification of Japan under the might of Seito, it was at this point that "Mido" ultimately dropped his guise and revealed himself as Evolto, the extra-terrestrial lifeform who would have consumed the Earth, though not before challenging the Kamen Riders to a last stand. An Oath to Be The One

New World

In the new world, he is a member of Prime Minister Himuro's new cabinet and serves as Japan's Minister of Foreign Affairs.


Similar to Tajimi, Mido's previously personality prior to the Sky Wall Disaster is unknown. Afterwards, the man became a power-hungry maniac with little remorse for any of his actions. He also shows himself to be rather cunning, as he purposely waited for Touto and Hokuto to battle each other, then take out the loser. In Tajimi's case, Mido jumped at the opportunity to wipe out her entire army when he saw that she practically left herself, and by extension Hokuto, in an all-or-nothing approach by sending out her entire military force. He is also rather smug, confident in Namba's subordinates that they would emerge the victors in their battle against Team Build.

Despite his negative traits, however, Mido was not without honor. Even though he was greatly frustrated by his loss, he was fully willing to return the Pandora's Box and the Fullbottles over to Touto, the only thing that any Build's higher up villain will never willing to do.

Behind the Scenes


Masakuni is portrayed by Norimasa Fuke (冨家 規政 Fuke Norimasa), who previously guest-starred in Samurai Sentai ShinkengerIcon-crosswiki.png as Mamoru ShiraishiIcon-crosswiki.png, father to Mako Shiraishi/ShinkenPink.


  • Mido serves as a foil to Tajimi. Tajimi, like others affected by the light produced by the Pandora's Box, was power-hungry and was willing to attack Touto in the event the Touto Rider Representative with Hokuto's entire military force. Mido, in contrast, was willing to honor the terms of his agreement with Touto and begrudgingly accept his loss.



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)