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

"I'll beat you in (number) move(s)."
―Amazon Sigma's taunting before the battle[src]

Jun Maehara (前原 淳 Maehara Jun) was the scout of the Nozama Peston Service. After his death at the hands of Dragonfly Amazon he was revived by transplanting Amazon Cells into his corpse. He uses the Amazons Driver to become Kamen Rider Amazon Sigma (仮面ライダーアマゾンシグマ Kamen Raidā Amazon Shiguma).


  • Identification code:Unknown
  • Rank:Unknown
  • Destroyed by: Mole Amazon


First death


Jun is originally a member of the Nozama Peston Services, and an Amazon hunter. He is untimely killed during the hunters' confrontation with the Dragonfly Amazon, formerly Ryusuke Otaki, attempting to get through to his former comrade only to be mauled by the hungry Amazon. Mortally wounded, Maehara takes solace in that, though fated to die at the hands of one of the beasts, it was Otaki who did so, before he dies. BEAST INSIDE


Nozama Pharmacy, lead by Yugo Tachibana, then implanted Amazon Cells into his dead body, reanimating him, resulting in him turning into his Amazon Origin Form. He is also seen in a cage, chained, waiting for the moment to go outsideHERO OR NOT

Amazon Sigma face to face to Alpha

Amazon Sigma vs Alpha

Takaaki Tenjo ordered Shogo Kano to give Jun the newly developed Amazons Driver, allowing him to transform into Amazon Sigma, an Amazon similar in appearance to Alpha and Omega. His first deployment was as a trap to kill Jin Takayama, where Yugo Tachibana sent an e-mail to him,  mentioning "a new type of Amazon". He was easily able to overpower Amazon Alpha, severely wounding him and forcing him to retreat.INTO THE CANNIBAL'S POT

In the next encounter between him and Nozama Peston Services, he then overpowers Amazon Omega, even managing to deliver a near-fatal blow through Omega's torso. JUNGLE LAW

Afterwards, he received a maintenance check in Nozama Pharmacy. His next deployment was to intercept Jin, who was chasing the Tlaloc switch stolen by Shogo Kano. Again, he managed to defeat Alpha even more easily, though this time Jin didn't fall, stating that he simply didn't want to, which the dead would never understand.

Immediately after, Nozama Peston Services and Haruka came, with Jin recovering and joining the fray not long after. In the ensuing battle, Amazon Sigma was able to fight more than evenly against the Alpha-Omega duo, until he was caught off-guard by an electric bullet combination from Kazuya Misaki and Kota Fukuda, his previous teammates. Taking the chance, Amazon Alpha hit him with the Violent Slash, followed by Omega's Violent Strike.

Second Death

Jun killed by Mamoru

Even after all of the punishment he received, Amazon Sigma was still able to stand as if nothing happened. However, it turned out that he just didn't feel pain; his body started to dissolve, the damage to it finally taking its toll. When he realized this, it was too late. Upon him attempting to escape, his torso was impaled from behind by Mole Amazon, killing him. KILLING DAY

The news of his death reached the Chairman of Nozama Pharmacy quickly, who became enraged, thinking that he was being used as an "accessory to failed research" by Yugo Tachibana. He then stated that despite Amazon Sigma's power, a lifeform who doesn't eat is garbage.

It is very likely that the project was discontinued and no other Amazon Sigma was produced anymore, except for one Five years later.

Video Game appearances

Kamen Rider Buttobasoul

Kamen Rider Amazon Sigma medal

Kamen Rider Amazon Sigma is a playable character in Kamen Rider Buttobasoul.

Powers and Abilities

Little was known about Jun's abilities while he was a living human, other than him being a skilled hacker and fighter, as well as an accomplished chess player, the latter of which is often referenced in his fights as an undead Amazon, used for taunting his opponents as to how many moves he would take to finish them off.

As a biological weapon designed and built to surpass the 'old' Amazon in every way, his basic fighting abilities as an undead Amazon is easily on par with that of Alpha's and Omega's, while his lack of morality and sense of pain boosts his parameters significantly, enabling him to easily take on Alpha or Omega on one-on-one fights, and almost defeating them altogether after being upgraded. However, his lack of sense of pain also serves as his weakness as he is unable to gauge the damage he has taken in fights, causing him to overexert himself all the time, thereby taxing his regenerative abilities heavily.

As an undead with no need, as well as being incapable, of consuming food, he is forced to rely on researchers back in Nozama Pharmacy for maintenance of his wellbeing. His overall abilities are also dependent on how good said researchers are at their jobs in maintaining and upgrading him, as he is thoroughly incapable of growth in any way. This makes him a deadly yet easy to control weapon.


Sigma Driver-less.jpg
Amazon Origin (アマゾン素体 Amazon Mototai)[1] is Amazon Sigma's initial form before equipping the Amazons Driver. In his case, it appears to be identical to his default form. This form is exclusive to S1 Episode 8

Amazon Sigma

Amazon Sigma

―Transformation announcement[src]

Rider Statistics:

  • Height: 186.5 cm[2]
  • Weight: 91.9 kg[2]

Ability Parameters:

  • Punching Power: 23.3 t[2]
  • Kicking Power: 29.1 t[2]

By using the specialized Amazons Driver made by Tachibana and his crew, it allows Jun to transform into Amazon Sigma.

Thanks to the newly developed Amazon Cells that are implanted in his body, he doesn't need to eat to restore his energy to transform again. Also, the belt allows him the ability to not feel pain, which acts both as an advantage and an disadvantage, as shown during his debut and his death.


  • Sigma Header (シグマヘッダー Shiguma Heddā): Sensor Antenna. Able to detect noise and enemy presence in his surroundings.
  • Amazon Eye (アマゾン・アイ Amazon Ai): Able to change focus at will and catch a target 1k meter away even if they are at high speed.
  • Crusher (クラッシャー Kurasshā): Sigma's fang. Sharp fangs which can easily chew through steel.
  • Converter Lung (コンバーターラング Konbātā Rangu): Sigma's chest. With the Amazons Driver's influence, the Amazon cells harden themselves to protect the core inside by cancelling almost all damage. It can also absorb heat and wind from the surrounding and convert it to stock energy.
  • Shell Break Arm (シェルブレークアーム Sheru Burēku Āmu):Arm cutter that can give the enemy severe damage to the internal hub.
  • Shell Break Leg (シェルブレークレッグ Sheru Burēku Reggu): Boot cutter that can momentarily activate the cell and enhanced motor function.
  • Knee Hex (ニーヘクス Nī Hecusu): Knee protector that can observe the quake and strengthen the knee.
  • Wilder Crust (ワイルダークラスト Wairudā Kurasuto):A skin that can moderately fasten and stretch the joints and muscles, also can change the hardness of parts of the body to defend from an enemy's attack.


  • Violent Strike

Appearances: S1 Episodes 9-11



Behind the Scenes


Jun Maehara is portrayed by Hiroshi Asahina (朝日奈 寛 Asahina Hiroshi). As Amazon Sigma, he is portrayed by suit actor Makoto Arakawa (荒川 真 Arakawa Makoto).

Concept Art


Dark Amazon


See Also


Kamen Riders
Haruka Mizusawa - Jin Takayama - Jun Maehara - Chihiro - Einosuke Mido
(Neo) Amazons Driver - (Neo, Militant) Amazons Register - Junglaider
Other characters
Mizuki Mizusawa - Nanaha Izumi
Nozama Peston Service
Makoto Shido - Ryusuke Otaki - Nozomi Takai - Kazuya Misaki - Kota Fukuda - Jun Maehara - Mamoru
Nozama Pharmacy
Reika Mizusawa - Shogo Kano - Yugo Tachibana - Takaaki Tenjo
Team X
Hiroki Nagase - Kenta Kitamura - Takumi Yamashita - Chihiro
Yugo Tachibana - Shogo Kano - Takeshi Kurosaki - Ichiro Fudamori - Kota Fukuda - Iyu Hoshino - Mizuki Mizusawa
Experiment Amazonz
Spider Amazon 1 - Spider Amazon 2 - Bat Amazon 1 - Dragonfly Amazon - Mole Amazon - Queen Ant Amazon - Soldier Ant Amazon - Butterfly Amazon 1 - Butterfly Amazon 2 - Shrike Amazon 1 - Shrike Amazon 2 - Crab Amazon - Bat Amazon 2 - Wasp Amazon 1
Sigma type Amazonz
Amazon Sigma - Crow Amazon
New type Amazonz
Vulture Amazon - Panther Amazon 1 - Stag Beetle Amazon - Rhinoceros Amazon 1 - Snake Amazon 1 - Mantis Amazon 1 - Urchin Amazon - Baboon Amazon - Elephant Amazon - Weevil Amazon - Rose Amazon - Mantis Amazon 2 - Rhinoceros Amazon 2 - Panther Amazon 2 - Snake Amazon 2
Lysogenic type Amazonz
Amazon Neo - Jellyfish Amazon
Livestock Amazonz
Buffalo Amazon - Sea Snake Amazon - Shark Amazon - Snapping Turtle Amazon - Squirrel Amazon - Tiger Amazon
Community content is available under CC-BY-SA unless otherwise noted.