This article is about a/an rider in Kamen Rider Kiva.

Otoya Kurenai (紅 音也 Kurenai Otoya) was a violinist, and the primary user of the original IXA system. He was notable for being the only human to transform into Kamen Rider Dark Kiva, although the strain from doing so cost him his life.

Character History

Otoya Kurenai is Wataru's father who battles the Fangire menace in 1986, his ideology that "All humans are music" his reason of fighting Fangires was to protect that music. Otoya was a ladies man who retires from being a professional violinist for reasons unknown. It was by accident that he interferes in Yuri Aso's mission and was eventually brought into their group as a result. Though normally a casanova, Otoya was vexed on anything marriage related, things always staying the same, and others getting in his way. He was the first to learn Jiro is actually a Wolfen, although no one believes him until later when Jiro threatened Yuri and reveals himself. He then becomes the second user of the Ixa System when Jiro was exposed, putting up a front of not suffering the suit's side effects.

He was also capable of reasoning with Fangires (and the other Demonic Races) who are not truly evil, an example being that he befriended Ōmura/Frog Fangire as he convinces him not to harm others. During his battle with the Fangire Race, Otoya falls in love with Maya, the original Queen of the Checkmate Four, resulting in the chain of events that led to him becoming the second Dark Kiva after forming a pact with Kivat-bat the 2nd to take on the Fangires' King. Otoya, with help from a time-traveling Wataru, succeeds in destroying the King at the cost of being on the verge of death due to the strain of wielding Kiva's power. After assuring Wataru along with Maya before parting with him, Otoya would then pay final visits to his friends Yuri and the Arms Monsters (seemingly as a ghost) before finally dying in Maya's arms after playing her favorite song. He would leave behind the Bloody Rose, a violin that Otoya himself made with Maya's help, for Wataru.

However, in a strange turn of events in 2008, Otoya's spirit makes his appearance when he suddenly finds himself in Wataru's body due a fail attempt of a fortune teller to do the ritual for learning Kiva's identity. During that time, he recognized Megumi and Kivat as the children of those from his time and also starts building a new violin with Wataru unaware that his father was building it through him. He would appear to Wataru in spirit one final time, encouraging his son not to give up as he lives on through him. He was later mentioned by his future grandson Masao whom he was compared with Otoya. In the non-canon The Queen of the Castle in the Demon World net spin-off movies, Otoya is brought into the present and bought the Café mald'amour, renaming it the "Café Otoya D'amour" and attempting to remodel it.


Otoya was a strange and eccentric womanizing man. While on one hand he has ruined the lives of others through his antics, he has also helped others change their lives for the better. Some of these people he helped change like Omura, Jiro and Maya remember him fondly and respects him greatly, being known as a "great man".

Despite his oddness, Otoya is hinted to have a lot of life force with in him as he managed to live despite having his life energy drained by Castle Doran itself. He also managed to transform into Dark Kiva (also managing to transform into Ixa once then badly being beaten by the Bat Fangire between his second and third transformations) three times despite Maya stating that a normal human will die after becoming Dark Kiva even once.

Although he didn't appear to be the best role model, his son also respects him greatly and wished to meet him. When they do indeed meet, and Otoya learns that Wataru is his son, Otoya in his own way acted as a father for Wataru showing how much he can care for others. After finding out from Maya that King was holding baby Taiga hostage, he was willing to consider Taiga as his child and rescue him.

Even after sacrificing himself to stop the Bat Fangire, Otoya continues to support his son in spirit and encouraged him to not give up when Wataru was fighting the revived Bat Fangire.



  • Hand-to-Hand Combat: Otoya initially had little experience in fighting but soon learned more as he joined Yuri and the gang as he fought Fangires. His strength was fully shown when he, along with his son, managed to defeat the Bat Fangire despite it`s seemingly overwhelming powers.
  • Masterful Violinist: Otoya was known for his prodigious violin skills.
  • High Endurance: Otoya had an exceptionally high tolerance for pain, which allowed him to handle the strain put upon his body by the unstable IXA system and still fight effectively.
  • Abnormally Robust Physiology: Otoya was known to be unusally robust as a human, always appearing to be full of life and easily excel at physical activities despite his inexperience in them. Not only did he survive having more than half of his lifeforce sucked by Castle Doran, he proceeded to transform into Dark Kiva not long after & fought effectively with it--something which should have immediately cost him his life due to him being a full-blooded human. As the first human to not only have transformed into Dark Kiva but survived, he proceeded to transform into Dark Kiva for two more times despite the danger posed to his body, which was already falling apart due to his previously mentioned ordeals, and survived intact on both occassions still. He only finally died having succumbed to the effects of using Dark Kiva's powers excessively, but still with enough time for him to realize his end was near and say his farewells to his friends.
  • Good Balance: Like all Kurenai's, Otoya had the unique ability of being able to walk on the balls of his toes.


Save Mode
KR-IXA SaveMode

Kamen Rider Ixa

"Fist On!"
―Transformation announcement[src]

Rider Statistics:

  • Rider height: 218 cm
  • Rider weight: 160 kg
  • Ability perimeters:
    • Punching power: 4.2 t
    • Kicking power: 1.8 t
    • Maximum jump height: 18 m
    • Maximum running speed: 100 m/9.6 s

The IXA system, an acronym for Intercept X Attacker, is a Rider System developed for fighting Fangire. Otoya uses the Prototype Version of the Ixa System, which only has access to Save Mode (セーブモード Sēbu Mōdo).

In 1986, the Ixa System was still in development. There were several technical problems such as the armor shooting out steam, a constant beeping, and the Ixa Knuckle producing sparks when activating a Fuestle. In addition, Ixa only has access to the Knuckle Fuestle. In contrast to the 2008 versions, the Ixa Knuckle had a deeper tone of voice and uses a bronze projection for the Ixa System's transformation. The Ixa Prototype Version exhausts a qualified person's body considerably even if they are not human, as the System still managed to harm both Jiro and Rook. Prolonged usage of the IXA system caused Otoya to develop temporary amnesia.

By inserting the Knuckle Fuestle into the Ixa Belt and pressing the Ixa Knuckle, Ixa can perform the Broken Fang (ブロウクン・ファング Burōkun Fangu) finisher.

Appearances: Kiva Episode 13-14, 16, 25, 27-31, 41-46, 48 (briefly helping out Wataru from the cliff), King of the Castle in the Demon World

Dark Kiva
KR-Dark Kiva

Kamen Rider Dark Kiva

―Dark Kivat's transformation announcement[src]

Rider Statistics:

  • Rider Height: 205 cm[1]
  • Rider Weight: 112 kg[1]
  • Ability perimeters
    • Punching power: 20 t[1]
    • Usual kicking power: 35 t[1]
    • Maximum jump height: 250 m[1]
    • Maximum running speed: 100 m. per 1.2 sec[1]

With Kivat-bat the 2nd, Otoya became Dark Kiva, the only human ever to do. Dark Kiva only appears to have one form, similar to that of Kiva Emperor Form However, Dark Kiva does not require the use of a being such as Tatsulot to achieve this form, and has no chains on his body as Kiva needs to control his power. Like King, Otoya has access to a unlimited potential of power that is hindered within his successor such as telekinesis and the use of the Kiva insignia as a weapon.

As Maya would later explain, the human body is unable to handle the strain of becoming Kiva: a single usage is fatal to most humans. Otoya was able to become Dark Kiva a total of three times before finally dying due to the strain it put on his body. Shima also mentioned this when Wataru revealed his heritage to him.

Appearances: Kiva Episode 45-46



  • Ixa Belt: Transformation belt
  • Ixa Knuckle: Transformation device
  • Fuestles: Whistle-like devices that activate a function, depending on the Fuestle.

Dark Kiva

Behind the scenes


Otoya Kurenai is portrayed by Kouhei Takeda (武田 航平 Takeda Kōhei), who previously played Ken ShidouIcon-crosswiki in Chouseishin GransazerIcon-crosswiki & would later go on to play Kazumi Sawatari in Kamen Rider Build. As a child, he is portrayed by Ayumu Maruyama (丸山 歩夢 Maruyama Ayumu). As Kamen Rider Ixa, his suit actor is Jiro Okamoto (岡元 次郎 Okamoto Jirō), whereas the suit actor for Kamen Rider Dark Kiva is Eitoku (永徳 Eitoku).


  • Even though Otoya and Wataru have met through time travel, Otoya didn't recognize his own son when he entered his body as a ghost thus creating a time paradox.
  • Otoya is similar to Gai Yuki (Black Condor)Icon-crosswiki from Choujin Sentai JetmanIcon-crosswiki, especially in their womanizing ways. Both fell in love with a fellow heroine of their time - Yuri to Otoya and Kaori (White Swan)Icon-crosswiki to Gai.
  • According to Kouhei Takeda in his blog, Otoya's pose when transforming into Ixa is a homage to Takeshi Hongo's transformation pose as Kamen Rider 1.[2]
Kazumi Sawatari Dogtag
  • Takeda's future role as Kazumi Sawatari contains a reference to his role as Otoya in the form of a dogtag pun: 9 ( Ku), 0 ( Re), 7 ( Na), 1 ( I) , 0 ( O) 10 ( To), 8 ( Ya).
    • In another sheer coincidence, both transform into Riders with an upgraded form that will put them into mortal danger - Dark Kiva and Grease Blizzard, respectively. This is further enforced by how the risk posed is from the nature of the transformation(using Kivat II as a pure human and the Hazard-Level increasing effect of the Grease Blizzard Knuckle), and not the taken form.



  1. "TV Asahi's page for the Ixamet". Retrieved 2009-06-27.
  2. "TV Asahi's page for Burst Mode". Retrieved 2009-06-27.
  3. "TV Asahi's page for Rising Ixa". Retrieved 2009-06-27.
  4. "イクサ!バージョンアップだ!!". Retrieved 2008-10-31.
  5. "TV Asahi's page for Ixa Belt and the Ixa Knuckle". Retrieved 2009-06-27.
  6. "TV Asahi's page for the Ixa Calibur". Retrieved 2009-06-27.
  7. "イクサ!バージョンアップだ!!". Retrieved 2008-10-31.
  8. "TV Asahi's page for the Garulu Saber". Retrieved 2009-06-27.
  9. "TV Asahi's page for the Ixariser". Retrieved 2009-06-27.
  10. "Honda | お客様相談センター | 仮面ライダーのバイク(仮面ライダーイクサ)". Retrieved 2008-11-20.
  11. "TV Asahi's page for the Ixalion". Retrieved 2009-06-27.
  12. "TV Asahi's page for the Powerd Ixer". Retrieved 2009-06-27.
Wataru Kurenai - Kivat-bat the 3rd - Demon Imperial Dragon Tatsulot - Castle Doran - Shoodoran
The Arms Monsters: Jiro - Ramon - Riki
Gear: Kivat Belt - Fuestles - Demon Imperial Sword Zanvat Sword - Machine Kivaa
2008: Mamoru Shima - Keisuke Nago - Kengo Eritate - Megumi Aso
1986: Otoya Kurenai - Yuri Aso
The Fangires
The Checkmate Four:
1986: Queen I - King I
2008: Bishop - Rook - King II - Queen II
Pawns: Horse Fangire - Octopus Fangire - Moth Fangire - Sheep Fangire - Ryo Itoya - Prawn Fangire - Frog Fangire - Earwig Fangire - Rhinoceros Fangire - Seastar Fangire - Ladybug Fangire - Chameleon Fangire - Grizzly Fangire - Shark Fangire - Crab Fangire - Cicada Fangire - Warthog Fangire - Moose Fangire - Horsefly Fangire - Rat Fangire - Mantis Fangire - Seamoon Fangire - Silkmoth Fangire - Polar Bear Fangire
Takato Shiramine - Takashi Sugimura
Mummy Legendorga - Medusa Legendorga - Mandrake Legendorga - Gargoyle Legendorga - Antlion Legendorga
View • [Edit]

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