is a Japanese tokusatsu series that serves as the 17th installment in the Kamen Rider franchise and the eighth entry in the Heisei era.
Main characters Ryotaro Nogami is an optimistic yet unlucky young man who becomes Kamen Rider Den-O after picking up a and being convinced by Hana to help mankind. Over the course of the series, he discovers that he is a , an individual who can overpower Imagin attempting to possess him, exist outside of time, and is largely immune to timeline changes. Additionally, he forms bonds with Imagin who disagree with their kind's methods and allow him to assume stronger forms.
Utilizing a Rider Pass in conjunction with the , Ryotaro can transform into the base Kamen Rider Den-O . While transformed, he wields the , which can be reconfigured into varying forms that allow him to perform finishers. However, due to his lack of combat prowess and Plat Form's lack of offensive capabilities, Ryotaro initially allows his Imagin partners to possess him and assume combat-oriented forms tailored to their fighting styles. His personal vehicle is the motorcycle.
Later in the series, Ryotaro acquires additional items that can combine with his preexisting devices to achieve the following power-up forms: : Ryotaro's super form accessed by combining the Den-O Belt and the cellphone that allows him to fuse with all four of his Imagin partners at once. : An evolution of Climax Form that fuses with Sieg to grant a pair of bird wings. This form first appears in the film Cho Kamen Rider Den-O & Decade Neo Generations: The Onigashima Warship. : Ryotaro's final form accessed by combining a Rider Pass and the , which like the DenGasher can be reconfigured into varying forms, that allows him to channel his Imagin partners' abilities.
During the events of the film Saraba Kamen Rider Den-O: Final Countdown, Ryotaro is possessed by the Ghost Imagin, who forces him to utilize a Rider Pass in conjunction with the Yuuki Belt to transform into Kamen Rider Yuuki . While transformed, he wields the Ghost Imagin's sword, which allows him to perform the Full Charge.
Ryotaro is portrayed by .
Kotaro , as nicknamed by Hana, is Ryotaro's 11-year-old self who appears exclusively in the film Kamen Rider Den-O: I'm Born!. While living with his grandmother, he occasionally snuck out to cope with losing his parents. During one such excursion, he encounters the DenLiner crew amidst their efforts to stop Gaoh and ends up being possessed by Momotaros, who uses him to transform into a smaller version of Kamen Rider Den-O called to fight Gaoh's forces due to the present Ryotaro's memory loss voiding their contract. Following the battle, the DenLiner crew take Kotaro to see his parents during his birth before returning him to his proper time period.
Kotaro is portrayed by , who also portrays the de-aged Ryotaro in the Cho-Den-O series.
Hana/Kohana is a Singularity Point, passenger of the DenLiner, daughter of Airi and Yuto, and niece of Ryotaro who originates from a future that the Imagin destroyed. As the sole survivor, she vowed revenge on the Imagin and joined the DenLiner's crew to protect the timeline from them. In pursuit of this goal, she convinces Ryotaro to become Kamen Rider Den-O and often serves as an enforcer to keep his Imagin partners in line, though she eventually comes to see them in a better light. As her future is gradually recreated, Hana physically regresses to her childhood self and assumes the alias of , though she stays on the DenLiner and later becomes a member of the DenLiner Police to continue protecting the timeline.
Hana is portrayed by while Kohana is portrayed by .
Taros The are Ryotaro's Imagin partners. They would eventually become the to keep rogue Imagin in check.
Momotaros is a hot-headed and arrogant yet comedic Oni/namesake-themed Imagin who is more interested in fighting than helping other Imagin. After initially failing to possess Ryotaro, Momotaros reluctantly joins the DenLiner crew where he forms a contract with and fights alongside the former. In time, he becomes the self-proclaimed leader of Ryotaro's Imagin partners. He would eventually represent Kamen Rider Den-O as a whole in succeeding media in light of Ryotaro's absence.
In battle, Momotaros wields the . As Kamen Rider Den-O, he assumes the red-colored where he primarily wields the DenGasher in , which allows him to perform the Full Charge. He also controls the head and torso of (Super) Climax Form, though he can control the form's other sections as well, and can channel his power through the DenKamen Sword's Sword Mode.
During the events of the crossover film Kamen Rider × Super Sentai: Ultra Super Hero Taisen, the Game World version of Momotaros temporarily assumes the form of where he commands the DenLiner.
Momotaros is voiced by .
Urataros is a suave, charming yet deceitful sea turtle/Urashima Tarō-themed Imagin who encounters Ryotaro after possessing him to use his status as a Singularity Point to pursue personal freedoms. Despite his personality, the latter allows the Imagin to stay after sensing he has a good heart.
In battle, Urataros wields the staff. As Kamen Rider Den-O, he assumes the blue-colored where he primarily wields the DenGasher in , which allows him to consecutively perform the and Full Charges. He also controls the right arm of (Super) Climax Form and can channel his power through the DenKamen Sword's Rod Mode.
Urataros is voiced by .
Kintaros is a noble bear/namesake-themed Imagin with a sumo wrestler-like personality and fighting style who displays an obsession with making his opponents .
In battle, Kintaros wields the . As Kamen Rider Den-O, he assumes the yellow-colored where he primarily wields the DenGasher in , which allows him to perform the Full Charge. He also controls the left arm of (Super) Climax Form and can channel his power through the DenKamen Sword's Axe Mode.
Kintaros is voiced by .
Ryutaros is a childish dragon/Taro the Dragon Boy-themed Imagin and a former member of Kai's gang who displays a love of breakdancing and animals. Having laid dormant in Ryotaro until he is awakened by Issē's counseling, Ryutaros initially seeks to take over the DenLiner and kill Ryotaro as part of a deal with Kai. However, the Imagin develops a crush on Airi, abandons his plans, and joins the DenLiner's crew.
In battle, Ryutaros wields the shotgun. As Kamen Rider Den-O, he assumes the purple-colored where he primarily wields the DenGasher in , which allows him to perform the Full Charge. He also controls the legs of (Super) Climax Form and can channel his power through the DenKamen Sword's Gun Mode.
Ryutaros is voiced by .
Yuto Sakurai is a spoiled, immature, and wrathful former high school student who was recruited by his future self to become and utilize the steam locomotive to protect the timeline from rogue Imagin, though memories of him across the timeline are erased every time he uses his Rider powers. Taking his mission seriously, Yuto abuses his Imagin partner Deneb and initially sees Ryotaro as being unfit to be a Kamen Rider because of the latter's desire to protect people and for refusing to use dishonest methods. However, Yuto eventually warms up to him and takes on some of his traits.
Utilizing one of several green-colored in conjunction with the , Yuto can transform into Kamen Rider Zeronos . While transformed, he wields the , which has a for performing the Full Charge and a for performing the Full Charge. His personal vehicle is the motorcycle.
Later in the series, Yuto acquires a series of red-colored Zeronos Cards, which allow him to assume . In this form, he gains the ability to transform Deneb into the Gatling gun for his use in combat, which allows him to perform the Full Charge.
During the events of the web-exclusive series Kamen Rider Outsiders, an alternate universe Yuto from a world where he lost his loved ones and was involved in an undisclosed disaster that he failed to overcome accepts Zein's offer to eradicate malice as he acquires the belt and its corresponding Progrise Key from Sakuya Tachibana and George Karizaki, allowing him to transform into . While transformed, he can use one of several , based on the Rider Cards, to gain the abilities and/or weaponry of the corresponding Kamen Rider. However, each Zein Card is only usable once, as they will be shredded after being used in the Zein Driver. His finishers are the and the .
Yuto Sakurai is portrayed by .
Yu is the nickname of Yuto's 11-year-old self who appears exclusively in the film Cho Kamen Rider Den-O & Decade Neo Generations: The Onigashima Warship. Having lost his mother to an unspecified disease and his father going away for a business trip, Yu is forced to move in with his grandmother in the countryside where he has trouble making friends. As a result of the Oni clan attempting to alter the present by rewriting the Momotarō folktale, Yu gets caught in the middle of the conflict between them and the DenLiner crew as he possessed the , an artifact passed down by his mother's ancestors that the Oni clan seek for their plot. In order to recover Yuto from the time distortion and help fight the Oni clan, Yu forms a contract with Deneb and eventually finds his courage once he is returned to his original time.
Yu is portrayed by .
Deneb is a polite and loyal yet over-apologetic crow/Benkei-themed Imagin and Yuto's partner who serves as his butler, parental figure, and combat aide. Despite being abused by Yuto, Deneb stays with him out of loyalty to the former's future self.
As Kamen Rider Zeronos, Deneb utilizes one of several yellow-colored Zeronos Cards in conjunction with the Zeronos Belt to assume where he is equipped with the twin shoulder-mounted cannons.
Deneb is voiced by .
Recurring characters Airi Nogami is Ryotaro's older sister and owner of the library/café, which previously belonged to their parents, who serves as a motherly figure to him, and the object of several young men's affections, though she remains oblivious to their advances. She was originally meant to marry Yuto prior to the series, having becoming pregnant with Hana, but Sakurai was forced to erase himself and their child from Airi's memories to protect her from Kai. Nonetheless, she retains trace amounts of her time with him, which manifests as a feeling that something is missing. By the series finale, she regains her memories of him.
Airi is portrayed by .
Seigi Ozaki is a journalist, chief editor of a short-lived magazine, and a regular at the Milk Dipper who seeks to restore the magazine. While he primarily seeks Airi's affections, he has flirted with other women since childhood.
Seigi Ozaki is portrayed by .
Issē Miura is an introverted and self-styled "super counselor" and a regular at the Milk Dipper who also vies for Airi's affections.
Issē Miura is portrayed by .
Naomi is the hyperactive and perky yet level-headed waitress of the DenLiner's dining car who, despite her best efforts, often makes coffee that tastes terrible to humans, but is irresistible to Imagin.
Naomi is portrayed by .
Owner The serious yet eccentric of the time-traveling bullet train is a Singularity Point who is knowledgeable in the timeline's inner workings, speaks in complex riddles when discussing its nature, and displays zero tolerance for those who fight on the DenLiner and violate the flow of time. He is also known for eating dishes, usually rice or flan, adorned with a flag, and attempting to finish the meal without knocking the flag over as part of a rivalry he shares with the Station Master. During the events of the film Kamen Rider Den-O & Kiva: Climax Deka, the Owner establishes the DenLiner Police, names himself its Chief Inspector, and takes up a DenGasher modified to shoot tranquilizer flags.
The Owner is portrayed by , who also portrays the Station Master.
Past Man