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).

Character History

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, reanimated him and give him the third Amazons Driver, allowing him to transform into Amazon Sigma, an Amazon similar in appearance to Amazons Alpha and Omega.

His first deployment was as a trap to kill Jin Takayama, where Yugo Tachibana sent e-mail to Jin mentioning "a new type of Amazon". He was easily able to overpower Amazon Alpha, severely wounded him and forced him to retreat.INTO THE CANNIBAL'S POT

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

Afterward, he received maintenance and upgrades 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 Amazon 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 Service and Haruka/Amazon Omega came, with Jin recovering and joined 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 electrified bullets combination of Kazuya Misaki and Kota Fukuda, his previous teammates. Taking the chance, Amazon Alpha hit him with Violent Slash, followed by Omega's Violent Strike.

Even after these, Amazon Sigma was still able to stand as if nothing happened. However, it turned out that he just didn't feel the pain; his body started to dissolve due to the battle damage. 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 "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.

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

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.

Amazon Sigma
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).



Kamen Rider Amazon Sigma concept Art


  • Kamen Rider Amazon Sigma's appearance is identical to Haruka Mizusawa's Amazon Origin form, just with a different color scheme and the Amazons Driver.
    • Sigma's color scheme is highly reminiscent of a red-bellied piranha.
  • Jun shares similarities to the Necro-Overs from Kamen Rider W.
  • He and Jin are presumably the only Amazons who don't need to use an Amazons Register to control themselves.
  • In the western release of Kamen Rider Amazons, Amazon Sigma is known as Amazon Rider Sigma.
  • Ironically, the cause of both his deaths was by his teammates from Nozama Peston Service; as a human, he was killed by his comrade-turned-Amazon Ryusuke Otaki/Dragonfly Amazon, and as Amazon, he was killed by Mamoru/Mole Amazon.
  • He is the only Amazon Rider (along with the movie-exclusive Amazon Neo Alpha) not to have a Ridewatch representing his Rider form.


See Also


Kamen Riders
Haruka Mizusawa - Jin Takayama - Jun Maehara - Chihiro - Einosuke Mido
(Neo) Amazons Driver - (Neo) Amazonz 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
Sigma type Amazonz
Amazon Sigma - Crow Amazon
New type Amazonz
Vulture Amazon - Panther Amazon - Stag Beetle Amazon - Rhinoceros Amazon - Snake Amazon - Mantis Amazon - Urchin Amazon - Baboon Amazon - Elephant Amazon - Weevil Amazon - Rose Amazon - Leopard Amazon 2
Lysogenic type Amazonz
Amazon Neo - Jellyfish Amazon
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