Ryotaro Nogami/Kotaro

Kotaro is the eleven-year old Ryotaro Nogami� met during the events of Kamen Rider Den-O: I'm Born!

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.

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 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.