Kamen Rider Series:

Kamen Rider Decade



First Appearance:

Kamen Rider Decade Episode 4 : 2nd Movement: Prince Kiva

Last Appearance:

Kamen Rider x Kamen Rider Double & Decade Movie War 2010

Number of Episode Appearances:

4(Decade) 1(Movies)


Arashi Fukasawa

Wataru (ワタル, Wataru) is a twelve-year-old half-Fangire boy, having the ability to transform into Kamen Rider Kiva (仮面ライダーキバ, Kamen Raidā Kiba?) with the aid of Kivat-bat the 3rd. Referred to as the Prince (王子, Ōji?) by his servants, Wataru is reluctant to claim the title of King (キング, Kingu?) of the Fangires. He finds the overseeing the ceasefire between humans and Fangires a very troublesome and unnerving task.


Wataru first meets Tsukasa and Natsumi at Kurenai Manor where he is playing his violin. Later during a misunderstanding, Wataru transforms into Kiva to fight Decade, who he believes is the devil. Yuusuke arrives and clears up the misunderstanding, offering his aid to Wataru and his task of serving as King. The next day, Wataru is confronted by the Beetle Fangire who intends to become the new King. The Beetle Fangire successfully claims Kivat as his own in the ensuing battle and proceeds to absorb the Arms Monsters into his Fangire armor, allowing him to become Kiva DoGaBaKi Form. After listening to Tsukasa make a speech about his ideals for the coexistence of humans and Fangire, Wataru takes back the power of Kiva, teaming with Decade to fight the Beetle Fangire. With a combination attack of Decade's Dimension Kick and Kiva's Darkness Moon Break, the Riders defeat the Beetle Fangire, who is later revealed to be Wataru's father, the former King. He later appears in the World of the Rider War as his reality is absorbed into it. Leading the Riders of his world, Wataru refuses to listen to Tsukasa and Yusuke in uniting all Riders to defeat Dai-Shocker and stop the convergence of the worlds, while in grief over IXA's death. He even went so far to allow the Queen of the Fangires, Yuki, to marry Apollo Geist for the World of Kiva to have an advantage over the other A.R. Worlds, but later changes his mind when the Fangire betrayed them to Dai-Shocker. After defeating Super Apollo Geist, the convergence of the worlds continues and the World of Kiva and Wataru disappear along with the World of Hibiki and Asumu after the destruction of Super Apollo Geist by Decade and Diend.

However, in Kamen Rider x Kamen Rider Double & Decade : Movie War 2010, he is resurrected after Tsukasa has been killed by Kamen Rider Kiva-la. He later appears alongside the Riders of the Nine Worlds to revive Tsukasa and help him battle Super Shocker, assuming Emperor Form with the help of Decade's K-Touch and later transform into the Castle Doran by the Final Form Ride All Rider Card to fight the Super Shocker.

Kamen Rider KivaEdit


Kiva Form

See Main Title : Kamen Rider Kiva's Form

Just like the original Kamen Rider Kiva had various forms into which he could change into for different powers and specialties, the Kiva appearing in Decade has this same ability. The forms Wataru has transformed into are Kiva Form (キバフォーム ,Kiba Fōmu), Garulu Form (ガルルフォーム ,Garuru Fōmu), Basshaa Form (バッシャーフォーム ,Basshā Fōmu), Dogga Form (ドッガフォーム ,Dogga Fōmu) and under the Beetle Fangire when he used the Kiva powers, DoGaBaKi Form (ドガバキフォーム ,Dogabaki Fōmu) (this transformation was direct due to the Beetle Fangire absorbing the Arms Monsters).

Final Form RideEdit


Final Form Ride, Kiva Arrow

Transforms Kiva into a large Kivat-like Bow with an arrow resembling Kiva's sealed Hell's Gate leg. In Kamen Rider x Kamen Rider Double & Decade : Movie War 2010, Wataru transform into the Castle Doran by the Final Form Ride All Rider Card to fight the Super Shocker.