The series has a time travel/multiverse motif while paying tribute to all of the previous Heisei-era Kamen Riders due to being a spiritual sequel to Kamen Rider Decade. The series and related films also feature returning actors reprising their roles from the previous Heisei series.
Sougo Tokiwa, a high school senior born in the year 2000, dreams of one day becoming a king. Suddenly, he meets a mysterious girl hailing from the year 2068, named Tsukuyomi, who comes with an ominous warning: Sougo will become Ohma Zi-O, the tyrannical Overlord of Time. Despite being troubled by his potential fate, Sougo becomes Kamen Rider Zi-O to save the space-time continuum from the Time Jackers, a group seeking to alter the history of the Heisei Kamen Riders for their ends. He is aided in his quest by Geiz Myokoin, a resistance fighter also from 2068 capable of becoming Kamen Rider Geiz who initially intended to kill Sougo to prevent his future tyranny, and a self-titled prophet named Woz, who wants the youth to become the tyrant Ohma Zi-O, who later gains the power to become Kamen Rider Woz. Along their journey, Sougo and his friends meet several Kamen Riders from the past and their allies; earning their trust and obtaining their powers.
Following his high school graduation, Sougo discovers that Swartz, the Time Jackers' leader, is Tsukuyomi's older brother and was manipulating both the Riders and his fellow Jackers in his plan to fuse the entirety of the Kamen Rider multiverse into a single, unified world to destroy it and save his world. Despite their best efforts, Sougo and his allies fail to stop Swartz until the former accepts his destiny and becomes Ohma Zi-O to destroy him. However, instead of taking control of the world as foretold of him, Sougo renounces his powers to undo Swartz's damage; creating a new reality where he lives in peace with Geiz, Tsukuyomi, and the other Time Jackers.
Production
The Kamen Rider Zi-O trademark was registered by Toei on April 12, 2018.[2]
As the show pays tribute to the Heisei period Kamen Riders, each tribute episode title consists of a short phrase related to a particular Heisei Rider series and a year relevant to it. Throughout the series, Zi-O's predecessor, Kamen Rider Decade's, involvement steadily becomes more prevalent, with "*" denoting episodes where his or his associate Kamen Rider Diend's involvement overlapped with another Rider's tribute episode.
Episode 17-30 - Ohma's Day: This arc features White Woz, who seeks to create Geiz Revive using the power of three future Riders, and the preparation of Ohma's Day. It also features tributes to Kamen Rider Ryuki and Blade*, as well as delves into Sougo's past.
Episode 31-40 - Road to the King: This arc delves into Tsukuyomi's past as she regains her memories. It also features tributes to Kamen Rider Agito, Hibiki, Kiva, Kabuto*, and Den-O.
Episode 41-49 - The New Lord*: This sees Swartz's real plan come to light and Sougo becoming Ohma Zi-O. It also features tributes to Kamen Rider Drive and the movie-exclusive Riders.
Kamen Rider Zi-O the Movie: Over Quartzer (劇場版 仮面ライダージオウ Over Quartzer, Gekijōban Kamen Raidā Jiō Ōvā Kwōtsā) was released on July 26, 2019, double-billed with Kishiryu Sentai Ryusoulger the Movie: Time Slip! Dinosaur Panic. Japanese boy band Da Pump portrayed the Quartzers, the movie's main antagonists, with Kamen Rider Barlckxs portrayed by Da Pump vocalist ISSA while Zyuden Sentai Kyoryuger's choreographer Papaya Suzuki and actor Syuusuke Saito portrayed Kamen Riders Zonjis and Zamonas respectively.[7][8][9][10] Additionally, Kamen Rider Drive's Yu Inaba and Chris Peppler returned to reprise their roles.[11] This film is a shared tribute to Kamen Rider Drive, the Heisei era's Showa era-themed Kamen Rider series (Black RX, Shin, ZO, J, and Amazons), and the entire Heisei Kamen Rider Series as a whole. It also introduced the first Kamen Rider of the Reiwa period, Kamen Rider Zero-One. This movie takes place after episode 43 and also serves as an alternate ending to the series.
A Movie War film, titled Kamen Rider Reiwa The First Generation (仮面ライダー 令和 ザ・ファースト・ジェネレーション, Kamen Raidā Reiwa Za Fāsuto Jenerēshon) was released on December 21, 2019, featuring the casts of Zi-O and Kamen Rider Zero-One.[12] This film is a shared tribute to Kamen Rider Zero-One, the original Kamen Rider, and the entire Heisei Kamen Rider Series as a whole. The events of the film take place after the end of the main series.
Special episodes
Kamen Rider Zi-O: Supplementary Plan (仮面ライダージオウ 補完計画, Kamen Raidā Jiō Hokan Keikaku) is a web-exclusive series released on Toei Tokusatsu Fan Club. It accompanies the airing of the main series' episode the day after it.
Episode 1.5: Mystery of Naming (ネーミングの謎, Nēmingu no Nazo)
Episode 2.5: Rules of the World (世界のルール, Sekai no Rūru)
Episode 4.5: Confession from A-Legends (Aレジェンドの告白, Ē Rejendo no Kokuhaku)
Episode 5.5: Sougo Tokiwa and the Mysterious Phone (トキワ荘ゴと謎電話, Tokiwa Sōgo to Nazo Denwa)
Episode 6.5: The Secret of Fourze 555 (フォーゼ555の秘密, Fōze Faizu no Himitsu)
Episode 7.5: Who Is the Worst Black? (最悪のブラックは誰だ, Saiaku no Burakku wa Dare da)
Episode 8.5: The Terrifying Time Paradox! (恐怖のタイムパラドックス！, Kyōfu no Taimu Paradokkusu!)
Episode 9.5: The King, God, and Adult (王と神とオトナ, Ō to Kami to Otona)
Episode 10.5: Mouri vs. Shimoyama (モーリ対シモヤマ, Mōri Tai Shimoyama)
Episode 11.5: Mysteries of 95DO! (謎の95DO！, Nazo no Kujigojidō!)
Episode 12.5: Interview With Future People (インタビュー・ウィズ・未来人, Intabyū Wizu Miraijin)
Episode 13.5: Ghost Teacher (ユーレイの先生, Yūrei no Sensei)
Episode 14.5: Pink Devil (ピンクの悪魔, Pinku no Akuma)
Episode 15.5: Supplementary Plan Forever: Part 1 (補完計画よ永遠に（前編）, Hokan Keikaku yo Eien ni (Zenpen))
Episode 16.5: Supplementary Plan Forever: Part 2 (補完計画よ永遠に（後編）, Hokan Keikaku yo Eien ni (Kōhen))
Rider Time is a web-exclusive spin-off series. Each comprises three episodes.
Kamen Rider Shinobi (仮面ライダーシノビ, Kamen Raidā Shinobi): Released on Toei Tokusatsu Fan Club on March 31, 2019, written by Kaori Kaneko, and directed by Takayuki Shibasaki. It features the Ninjutsu Tournament Chapter (忍術大会編, Ninjutsu Taikai-hen) of Shinobi, the hypothetical Kamen Rider Series of 2022. Aside from the newly introduced secondary Rider of 2022, Kamen Rider Hattari, it briefly shows four more unnamed ninja Kamen Riders in the third episode's ending.[13] The theme song is "IZANAGI", performed by Sakuramen feat. Hideya Tawada.[14] It is later followed by Geats Extra: Kamen Rider Tycoon Meets Kamen Rider Shinobi (ギーツエクストラ 仮面ライダータイクーンmeets仮面ライダーシノビ, Gītsu Ekusutora Kamen Raidā Taikūn Mītsu Kamen Raidā Shinobi) in 2023.[15]
First NinPow!: Hattari's Love Is Unrequited (FIRST 忍POW！ハッタリの恋はイッポウ通行の巻, Fāsuto Ninpō! Hattari no Koi wa Ippō Tsūkō no Maki)
Next NinPow!!: Yaminin's Assassination Technique (NEXT 忍POW!!闇忍の暗殺殺ポウの巻, Nekusuto Ninpō!! Yaminin no Ansatsu Sappō no Maki)
Last NinPow!!!: Dead End and Close Call (LAST 忍POW!!!八ポウ塞がり危機一髪の巻, Rasuto Ninpō!!! Happō Fusagari Kikiippatsu no Maki)
Kamen Rider Ryuki (仮面ライダー龍騎, Kamen Raidā Ryūki): Part of the spin-off collaboration with the titular Kamen Rider of 2002. Released on Video Pass on March 31, 2019, written by Toshiki Inoue, and directed by Takayuki Shibasaki, the storyline is a sequel to the original Ryuki TV series, which features the sudden revival of the Mirror World's Rider War. Takamasa Suga, Satoshi Matsuda, Hassei Takano, Satoshi Ichijo, Tomohisa Yuge, Takashi Hagino, and Tsuyoshi Koyama reprised their respective roles. It also introduces Kamen Rider Abyss from Kamen Rider Decade to the main universe[16] and features appearances by Zi-O and Geiz. The theme song is "Go! Now! ~Alive A life neo~", performed by Rica Matsumoto.[17] Even though Kamen Rider Zi-O producer Shinichiro Shirakura says this storyline takes place before episode 21,[18] it may actually take place between episodes 28 and 29, as evidenced by Zi-O not having Ryuki's Ridewatch until the events of the latter episode.
Advent Again
Another Alternative
Alive a Life
Kamen Rider Zi-O vs. Decade: 7 of Zi-Os! (仮面ライダージオウVSディケイド 7人のジオウ！, Kamen Raidā Jiō Tai Dikeido Shichi-nin no Jiō!): Released on Telasa on February 9, 2021, written by Toshiki Inoue, and directed by Satoshi Morota.[19] The theme song is "INSIDE-OUT ZI-O ver.", performed by Sougo Tokiwa (So Okuno) & Tsukasa Kadoya (Masahiro Inoue).[20]
The Drifting School (漂流学園, Hyōryū Gakuen)
Eve of the War (戦争前夜, Sensō Zen'ya)
The Last Sougo (最後のソウゴ, Saigo no Sōgo)
Kamen Rider Decade vs. Zi-O: The Decade House Death Game (仮面ライダーディケイドVSジオウ ディケイド館のデス・ゲーム, Kamen Raidā Dikeido Tai Jiō Dikeido Yakata no Desu Gēmu): Released on Toei Tokusatsu Fan Club on February 9, 2021, written by Toshiki Inoue, and directed by Satoshi Morota.[19] This series takes place before Kamen Rider Zi-O vs. Decade: 7 of Zi-Os!. Additionally, Ryouta Murai (Kamen Rider Decade) reprised his role. The theme song is "INSIDE-OUT DECADE ver.", performed by Tsukasa Kadoya (Masahiro Inoue) & Sougo Tokiwa (So Okuno).[20]
The First Stage
The Next Stage
The Final Stage
Kamen Rider Bi Bi Bi no Bibill Geiz (仮面ライダービビビのビビルゲイツ, Kamen Raidā Bi Bi Bi no Bibiru Geitsu) is Televi-Kun's "Hyper Battle DVD" (超バトルDVD, Haipā Batoru Dī Bui Dī) for Kamen Rider Zi-O. The events of this specials takes place before episode 45.
Kamen Rider Zi-O Next Time
Kamen Rider Zi-O Next Time: Geiz, Majesty (仮面ライダージオウ NEXT TIME ゲイツ、マジェスティ, Kamen Raidā Jiō Nekusuto Taimu Geitsu, Majesuti) is a V-Cinema release that focuses on a side story starring Geiz Myokoin. The events of the V-Cinema take place after the end of the main series and Kamen Rider Reiwa: The First Generation. The V-Cinema is written by Nobuhiro Mouri and directed by Satoshi Morota and was released on April 22, 2020.[21]Kimito Totani (Kamen Rider Decade), Kōhei Murakami (Kamen Rider 555), Minehiro Kinomoto (Kamen Rider W), and Hiroaki Iwanaga (Kamen Rider OOO) returned to reprise their respective roles.[22] The theme song is "Brand New Day" performed by Triplane.[23]
Novel
Kamen Rider Zi-O (仮面ライダージオウ, Kamen Raidā Jiō), written by Kento Shimoyama, is part of a series of spin-off novel adaptions of the Heisei Era Kamen Riders. The events of the novel take place after the end of the main series. The novel was released on July 28, 2021.
Video game
Kamen Rider: Climax Scramble, known in Japan as Kamen Rider: Climax Scramble Zi-O (仮面ライダー クライマックススクランブル ジオウ, Kamen Raidā Kuraimakkusu Sukuranburu Jiō), is the seventh installment of the Kamen Rider: Climax series. This game was released on November 29, 2018, for the Nintendo Switch.[24]
The following opening and insert themes from previous series are reused in Zi-O: "BELIEVE YOURSELF" from Kamen Rider Agito in episode 32 and "Kagayaki" from Kamen Rider Hibiki in episode 34.
