Icon-shin.png This article is about a/an villain in the film Shin Kamen Rider: Prologue.

Giichi Onizuka (鬼塚 義一 Onizuka Giichi) was the scientist assigned to be the partner of Daimon Kazamatsuri, during what he believed to be an experiment capable of curing disease. While the true nature of the experiment was to create new super soldiers for the syndicate, Onizuka himself harbored his own hidden agenda, to create a new breed of warrior, a fusion of grasshopper and man, and be their ruler. In following this pursuit, he deceptively sabotages both ends of the experiment, altering the DNA of both Shin Kazamatsuri and himself.

He possesses the ability to transform into Onizuka Rider (鬼塚ライダー Onizuka Raidā) or Transformed Onizuka (鬼塚変身体 Onizuka Henshin-tai), classified as a Cyborg Soldier Level 3 (改造兵士レベル3 Kaizou Heishi Reberu Surī) type mutant enhanced with the genes of grasshoppers. He was distinguished by his white eyes as opposed to the red eyes of Kamen Rider Shin.

Throughout the movie, Onizuka periodically transforms to wreak havoc upon the city to satisfy his own violent nature. It was through these attacks that he unintentionally triggers Shin's own mutant abilities, causing him to telepathically view Onizuka's serial killings in his dreams, and ironically enabling Shin to steel his resolve and become a hero.

Upon being confronted by Shin on his quest for answers, Onizuka attempts to subtly influence him to the true nature of his plans in an attempt to convince him to embrace his violent side. It backfires, as Shin is unable to comprehend his complex speech, and dismisses it, since Shin failed to get a direct answer.

Failing to recruit his only potential accomplice, Onizuka attempts to leave the syndicate and strike out against them, but is captured by their security force and placed in the trailer of a cargo truck. While being transferred to an unknown location, the truck is tailed by both Shin and the CIA. Upon being ambushed by the CIA, the syndicate's forces are defeated following the attack, and the trailer tumbles open, presenting Onizuka with an opportunity to escape. Taking the opportunity to instead kill the CIA agents, Onizuka attempts to transform, but was killed halfway via rocket launcher fire. Burning to death, he attempts to send a telepathic plea for help to Shin, which fails to reach him and instead induces Shin's own full transformation.

Through his dying actions, Onizuka ironically crushes any hope he had of achieving his goal, as Shin becomes not the pawn to Onizuka's own ambitions, but the hero to stand against the syndicate.


Transformed Onizuka

Onizuka Rider

Ability Parameters:[note 1]

  • Punching Power: 2~2.8 t
  • Kicking Power: 3~4.2 t
  • Bite Power: 0.5~0.6 t
  • Maximum Jump Height: 114 m
  • Maximum Jump Distance: 232 m
  • Maximum Running Speed: 100 m per 3.4 seconds

Evolved Form

Cyborg Soldier Level 3

In the Super Imaginative Chogokin toyline, Onizuka has a four-armed version of his Rider form.

Behind the scenes


Giichi Onizuka was portrayed by Kouki Kataoka (片岡 弘貴 Kataoka Kōki). As Transformed Onizuka, his suit actor is Jiro Okamoto (岡元 次郎 Okamoto Jirō), same as Kamen Rider Shin.[2]


Onizuka Rider's appearance is almost identical to Kamen Rider Shin except for a few minor differences: his eyes are white and smaller, while his fangs appear on the outside of his mouth.



  1. Takeshobo. (2001). Masked Rider Chronicles: A History of Cyborg Soldier's Battle. p. 206.
  2. Uchusen Vol.150 , p. 80


  1. Equivalent to Shin[1]

See also

Icon-shin.png Icon-zo.png Icon-j.png 90's Movie Trilogy
Kamen Riders
Shin Kazamatsuri - Masaru Aso - Kouji Segawa
Z-Bringer - J-Spirit - J-Crosser
Shin: Ai Asuka - Daimon Kazamatsuri - Takuya Yuuki - Shiin Kazamatsuri - Sarah Fukamachi
ZO: Hiroshi Mochizuki - Seikichi Mochizuki - Doctor Mochizuki - Reiko - Kuroda - Nishimura - Miyazaki
J: Kana Kimura - Earth Spirits - Berry
Foundation (Shin): Iwao Himuro - Goushima - Giichi Onizuka
Neonoid (ZO): Doras - Koumori Man - Kumo Woman

Fog (J): Fog Mother - Agito - Zu - Garai

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