is a Japanese tokusatsu drama produced by Toei Company and part of the Kamen Rider franchise. It is the twenty-ninth television series in the franchise and the twentieth and final installment of the Heisei period. The series premiered on September 2, 2018, following Kamen Rider Build's conclusion. It aired alongside Kaitou Sentai Lupinranger VS Keisatsu Sentai Patranger and later the miniseries Super Sentai Strongest Battle, before being joined by Kishiryu Sentai Ryusoulger in the Super Hero Time programming block.
The series incorporates a time travel and multiverse motif, serving as a tribute to the preceding Heisei-era Kamen Rider productions and functioning as a spiritual successor to Kamen Rider Decade. The series and its related films also feature returning actors reprising their roles from earlier Heisei entries.
Sougo Tokiwa, a high school senior born in 2000, dreams of becoming a king. He encounters Tsukuyomi, a mysterious girl from the year 2068, who warns him that he is destined to become Ohma Zi-O, the tyrannical "Overlord of Time." Despite his unease about this possible future, Sougo assumes the mantle of Kamen Rider Zi-O to protect the space-time continuum from the Time Jackers, a group attempting to alter the history of the Heisei-era Kamen Riders for their own purposes. He is assisted by Geiz Myokoin, a resistance fighter from 2068 who transforms into Kamen Rider Geiz and initially seeks to kill Sougo to prevent his rise to tyranny, and by Woz, a self-proclaimed prophet who supports Sougo's path toward becoming Ohma Zi-O and later becomes Kamen Rider Woz. Along their journey, Sougo and his allies encounter past Kamen Riders and their companions, earning their trust and acquiring their powers.
After graduating from high school, Sougo learns that Swartz, the leader of the Time Jackers, is Tsukuyomi's older brother and has been manipulating both Riders and his fellow Jackers in a plan to merge the entire Kamen Rider multiverse into a single world, which he intends to destroy in order to save his own. Sougo and his allies ultimately fail to prevent Swartz's scheme until Sougo embraces his destiny as Ohma Zi-O to defeat him. However, rather than ruling as foretold, Sougo sacrifices his powers to reverse the damage caused by Swartz, creating a new reality where he lives peacefully with Geiz, Tsukuyomi, and the remaining Time Jackers.
The trademark for Kamen Rider Zi-O was registered by Toei on April 12, 2018.
As the series pays tribute to the Heisei-era Kamen Rider productions, each tribute episode title includes a short phrase referencing a specific Heisei Kamen Rider series along with a year associated with it. The involvement of Zi-O's predecessor, Kamen Rider Decade, gradually becomes more prominent throughout the show. An asterisk (*) denotes episodes where his appearance, or that of his ally Kamen Rider Diend, coincides with another Rider's tribute episode.
The series is divided into four narrative arcs:
Kamen Rider Zi-O first appeared in a cameo in '.
was released on December 22, 2018, as part of the Movie War series. It featured the casts of Kamen Rider Zi-O, Kamen Rider Build, and Kamen Rider Den-O. Actor Shunsuke Daità  portrayed the main antagonist, the Super Time Jacker Tid, while Kenichi Takità  provided the voice of the Imagin Futaros.
In addition to the Build cast, several former Kamen Rider actors returned, including Toshiki Kashu (Kamen Rider Agito), Takamasa Suga (Kamen Rider Ryuki), Masahiro Inoue (Kamen Rider Decade), and Shun Nishime (Kamen Rider Ghost), who reprised their roles vocally. Takeru Satoh (Kamen Rider Den-O) reprised his role as Ryotaro Nogami in person. The film serves as a shared tribute to Kamen Rider Kuuga, Kamen Rider Den-O, and Kamen Rider W.
was released on July 26, 2019, as a double feature with Kishiryu Sentai Ryusoulger the Movie: Time Slip! Dinosaur Panic. The film featured Japanese boy band Da Pump as the Quartzers, the main antagonists. Da Pump vocalist ISSA portrayed Kamen Rider Barlckxs, while choreographer Papaya Suzuki (Zyuden Sentai Kyoryuger) and actor Syuusuke Saito portrayed Kamen Riders Zonjis and Zamonas, respectively.
Additionally, Kamen Rider Drive actors Yu Inaba and Chris Peppler reprised their roles. The film serves as a shared tribute to Kamen Rider Drive, the Heisei-era Kamen Rider productions with Showa-era themes (Black RX, ', ZO, J, and Amazons), and the entire Heisei Kamen Rider Series. It also introduced Kamen Rider Zero-One, the first Rider of the Reiwa period. The film takes place after episode 43 and provides an alternate ending to the series.
was released on December 21, 2019, featuring the casts of Kamen Rider Zi-O and Kamen Rider Zero-One. The film serves as a shared tribute to Kamen Rider Zero-One, the original Kamen Rider, and the entire Heisei Kamen Rider Series. Its events take place after the conclusion of the television series.
is a web-exclusive series released on the Toei Tokusatsu Fan Club. Each episode was made available the day after the corresponding broadcast of the main series.
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Released on the Toei Tokusatsu Fan Club on March 31, 2019. Written by Kaori Kaneko and directed by Takayuki Shibasaki. The theme song is "IZANAGI", performed by Sakuramen feat. Hideya Tawada.
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Released on Video Pass on March 31, 2019. Written by Toshiki Inoue and directed by Takayuki Shibasaki. The theme song is "Go! Now! ~Alive A life neo~", performed by Rica Matsumoto.
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Released on Telasa on February 9, 2021. Written by Toshiki Inoue and directed by Satoshi Morota. The theme song is "INSIDE-OUT ZI-O ver.", performed by So Okuno and Masahiro Inoue.
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Released on the Toei Tokusatsu Fan Club on February 9, 2021. Written by Toshiki Inoue and directed by Satoshi Morota. The theme song is "INSIDE-OUT DECADE ver.", performed by Masahiro Inoue and So Okuno.
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is the Televi-Kun for Kamen Rider Zi-O. The events of this special take place prior to episode 45.
is a V-Cinema release that serves as a side story focusing on Geiz Myokoin. The events of the film take place after the conclusion of the television series and '.
The V-Cinema was written by Nobuhiro Mouri and directed by Satoshi Morota. It was released on April 22, 2020. Kimito Totani (Kamen Rider Decade), KÃ Âhei Murakami (Kamen Rider 555), Minehiro Kinomoto (Kamen Rider W), and Hiroaki Iwanaga (Kamen Rider OOO) reprised their respective roles.
The theme song is "Brand New Day," performed by Triplane.
, written by Kento Shimoyama, is part of a series of spin-off novel adaptations of the Heisei-era Kamen Rider series. The events of the novel take place after the conclusion of the television series. It was released on July 28, 2021.
Kamen Rider: Climax Scramble, known in Japan as , is the seventh installment in the ' video game series. It was released on November 29, 2018, for the Nintendo Switch.