Keiji Onizuka

Keiji anime revenge artwork

Keiji artwork

Keiji Onizuka

Full name Keiji Onizuka
Japanese name 鬼塚 慶次(おにづか けいじ)
Romanization Onizuka Keiji
Surgery type Crustacean
Surgery base Odontodactylus scyllarus
Status Alive
Age 24
Gender Male
Birthday June 23 (Cancer)
Height 175cm
Weight 61kg
Origin Japan
Blood type O
Affiliations Annex I
M.A.R.S ranking #8
Manga Debut Chapter 13
Anime Debut Episode 1
Seiyuu Daisuke Ono
Image Gallery
Keiji Onizuka (鬼塚 慶次, Onizuka Keiji) is Japanese man under the tutelage of the Squad #1 leader Komachi Shokichi from the Annex I project.


Keiji is a well-built, fit man, with red hair and black eyes.

Personality Edit

Keiji is a man who cares about his fellow crew members, who he wants to protect at all costs, as well as humans in general. The latter is shown when he jumped to save Hong ,his enemy at that time, from a Terraformar.

Different from his fellow crew members Marcos E. Garcia and Akari Hizamaru Keiji is rather prudish around women as he was visibly uncomfortable with the prospect of drinking Echdina milk from Peggy Fortie's stomach and visibly embarrassed by the sight of a nude Xi Chun-Li. He also refuses to hit women and kept those words even when Xi damaged his ribs as well as one of his testicles.



Ever since he was a child; Keiji spent most of his time at home watching movies from around the world with his mother. Taciturn and lonely Keiji trained continuously and became a professional boxer. His body handled weight loss easily, so he had planned to drop down to super feather-weight and win the title after conquering the light-weight class but abandoned the idea once the symptoms of retinal detachment emerged. Keiji case required difficult surgery, and although the detachment was cured he required large sums of money to get to the point where he could regain his license. For this reason he joined the Annex Project.

Annex I Arc (2619 A.D.)Edit

After the six squads proceeded to execute Plan Delta, the Squad no. 1, led by Komachi Shokichi, encountered two transformed roaches - a Silk Moth Terraformar and a Pachyrhynchus Infernalis Terraformar. While Komachi started to fight with the silk moth one, Keiji had to confront the "hardest insect" roach. Once transformed, Keiji carried a good fight with the roach, striking and evading the terraformar's attacks, until he had a short moment of visual malfunction, which costed him a powerful blow from the roach, sending him flying into the the edge of the pit he and his captain were trapped in. But this didn't finish the boxer. With his right eye and left arm damaged, and fuelled by his goal to return to earth and show his loving mother that he will live a normal life, with friends and a lover by his side, Keiji delivered a final, thunderous, powerful blow right in the chest of the heavy Terraformar, thus finishing him off and winning the fight.

Powers and AbilitiesEdit

Keiji preparing to fight the Terraformar

Keiji's Transformation

Keiji is an experienced former professional southpaw boxer and lightweight world champion. He stopped after a heavy injury to his retina. He trains rigorously every day to keep himself in top physical condition. His fighting style requires a lot of stamina since he isnt a slugger but a counter-puncher that dodges before striking.

After receiving his M.O. Operation, Keiji gained the powers and abilities of the peacock mantis shrimp, making him incredibly strong and durable, being able to receive powerful blows from the Pachyrhynchus infernalis terraformer and eventually breaking its exoskeleton which is considered the hardest of any insect. He is also able to regenerate any lost limbs after few minutes with little effort. In addition to their powerful blows the mantis shrimp also possesses the most advanced eyes in the animal kingdom, enabling Keiji to detect light from near-infrared all the way to ultraviolet. This allows him to see clearly in pitch-darkness and also see right through Xi's camouflage which renders her completely invisible to the human eye.

He also possesses carapace-integrated power wrists named "Gonna Fly Now" that function as weights as well as protective armor. They can be removed if he wishes to sacrifice protection for a tremendous increase in speed. It is using this tactic that he managed to win against the peacock mantis shrimp terraformar created from his arm ripped off by the dragonfly terraformar.


  • Keiji likes sashimi (especially shrimp) and dislikes those who carry their umbrellas horizontally.
  • He takes the drug through what appears to be an opium pipe.

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