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Seito Flag and Emblem

Seito and its emblem.

Seito (西都 Seito) is the western region of Japan in the World of Build, created as a result of the Sky Wall, and is led by Prime Minister Masakuni Mido. Its system of governing and political goals are based on economic recovery, doing so in one effort by sending its young adults across the world to gather technical knowledge. The capital's crest of Seito is a star with a grain of wheat looped around it.

Seito is made up of the islands of Shikoku, Kyushu, and western Honshu.

Its unit of currency is the Ruruku (ルルク).[1]



Masakuni Mido, along with Yoshiko Tajimi and Gentoku Himuro at the return ceremony of INSET.

In 2008, the INSET exploration vessel Prominence returned from Mars to Earth, carrying astronaut Soichi Isurugi and an artifact he found on the planet, the Pandora Box. What was not known then, however, was that Isurugi had been possessed by an alien entity named Evolto while on Mars.

To commemorate his return, a ceremony was held in Japan with numerous dignitaries in attendance. However, calamity struck when Isurugi, compelled by Evolto, attempted to activate the Pandora Box as it was presented. Though he was soon restrained by security, this interference caused the erection of the immense Sky Wall, which split the island nation of Japan into three.

While many lives were lost in what would become known as the Sky Wall Disaster, others who were exposed to the light of the Pandora Box found their minds warped to crave power. Among the afflicted was Masakuni Mido, who would establish himself as Prime Minister of Seito, one of three now seperate nations created by the Sky Wall Disaster. Also sharing his condition were Yoshiko Tajimi, who became Prime Minister of Hokuto, and Gentoku Himuro, who would become Deputy Prime Minister of Touto; the elder Prime Minister Taizan Himuro had not attended the event and so retained his mental faculties.


In the bid to dominate Japan, Seito was the prefered choice of Juzaburo Namba, CEO of Namba Heavy Industries Ltd. To that end, Namba gave Mido his support with the full expsenses of Namba. The Phantom of the West

Seito initially stood as neutral when Hokuto invaded Touto. Eventually, however, Mido, knowing that the bulk of Hokuto's forces were engaged in Touto, sent Seito Guardians, led by the nation's own Kamen Rider, to seize Hokuto just as the proxy battle between Hokuto and Touto ended with the victory of Touto's Kamen Rider Build over Hokuto's Kamen Rider Grease. Sold out by Blood Stalk, Hokuto Prime Minister Yoshiko Tajimi was ordered taken into custody by Mido. Victory of Tears

Mido followed up the subjugation of Hokuto by declaring war on Touto. Having been provided with the new Kaisers created by Nariaki Utsumi based on the system developed by Kaisei Mogami: 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. Seito's Kaisers proved superior to both Hokuto's Hard Smashes as well as the Kamen Riders representing both Hokuto and Touto. They were second only to Seito's own Kamen Rider, Rogue, who made his way to Touto. 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


Following the War, the governor of Seito was Mitsuomi Gohara of the Blood Tribe. Kamen Rider Build: Be The One



See also


  1. Super Televi-Kun 2018
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)
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