Ryotaro Nogami/Kotaro


 * Not to be confused with Kotaro Nogami, Ryotaro's grandson, who became New Den-O

"Kotaro" is the eleven-year old version of Ryotaro Nogami that he met during the events of Kamen Rider Den-O: I'm Born!, nicknamed Kotaro to differentiate him from his present, older self.

He is played by Takuya Mizoguchi, who reprises his role as a deaged Ryotaro in Cho Kamen Rider Den-O & Decade NEO Generations: The Onigashima Battleship.

I'm Born
When Ryotaro and Hana are trapped in the year 2000 by Kamen Rider Gaoh they encounter Ryotaro's child self. With Ryotaro lacking memories of being Kamen Rider Den-O due to being attacked by Gaoh and unable to transform, the young Ryotaro is given the nickname Kotaro and decides to go with them to stop Gaoh's plans. During a fight with ninjas in the Edo Period, Momotaros possesses him with his contract to Ryotaro extending to the past and transforms into Kamen Rider Mini Den-O.

After the battle Kotaro is brought back to his time but not before seeing his late parents and then bids the gang farewell.

Sword Form
A form assumed when Momotaros possessed Kotaro during a fight between some of the ninja in the Edo period during Kamen Rider Den-O: I'm Born!

Onigashima
As a result of an unknown force altering the present Ryotaro is regressed into an adolenscent form. While investigating an error in time with Deneb and Kamen Rider New Den-O he encounters a child Yuto Sakurai. Later after finding three of the scattered Taros and going into the time of the battle against Oni Island Ryotaro reunites Momotaros and fights alongside everyone.

Despite being a child Ryotaro does not assume Mini Den-O instead becoming an adult Den-O. This is possibly because unlike Kohana who was regressed into a child due to her future being recreated Ryotaro was deaged as a result of an unknown tampering of time.