Kamen Rider

Kouji Segawa

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This article is about a/an feature film rider in the film Kamen Rider J.
Kouji Segawa
Kouji Segawa
Kamen Rider J
Gender: Male
Series: Kamen Rider J
Motif: Two-striped Grasshopper
Rider Type: Protagonist
Homeworld: Earth (Main Timeline Continuity)
First Appearance: Kamen Rider J
Last Appearance: Super Hero Taisen GP: Kamen Rider 3Icon-crosswiki
Number of Episode
7 (movies)
Full list of appearances
Actor: Yūta Mochizuki
Kouta Nemoto (All Riders vs. Dai-Shocker, Decade: Final Chapter)
Tetsu Inada (Kamen Rider Taisen)

Kouji Segawa (瀬川 耕司 Segawa Kōji) is Kamen Rider J (仮面ライダーJ Kamen Raidā Jei, Masked Rider J), the main protagonist in the Japanese tokusatsu movie Kamen Rider J.


Kamen Rider J

Kouji is an environmentalist reporter who was investigating the pollution of mountain lakes and forests in Japan. He was killed while attempting to protect his young friend, Kana and was thrown over the cliff by the Fog Mother's child Agito as Kana is taken by the insectoid Zu. However, Kouji was resurrected by the Earth Spirits as a J-Powered Warrior, Kamen Rider J, acting on their will to fight the Fog with their emissary Berry as his guide. With Fog Mother sensing Kouji's presence, Agito attempts to finish the job in his true form, only to be killed by J. Hurrying to Kana, Kouji enters their domain and faces Zu as she assumes her true form. Facing her, J manages to mortally wound Zu as she grabs him, taking to before they crash into the fortress which is Fog Mother.

After she dies, Kouji learns of Fog's intention of feeding humanity to Fog Mother's brood as Garai completes the ritual and sends Kana to the hatching chamber while manhandling Kouji. Berry intervenes to free Kana from Fog's spell before being struck down by Garai as Kana is sent down to her death while Fog Mother begins attacking a nearby city to prepare for her children's awakening. Assuming his Rider form, J fights Garai in his true form, Cobra Man, in a heated battle. After killing Garai, J is being digested by Fog Mother as he attempts to save Kana. However, absorbing the life energy around him, J kills off Fog's newly born spawn as he escapes the bowels of Fog Mother and assumes Jumbo Formation. After ripping Kana out of Fog Mother, J battles the monster before killing her as she attempted to take him down with her. Escaping Fog Mother's destruction, Kouji takes Kana to a serene environment with Berry watching from a distance.

Later Appearances in Kamen Rider/Super Sentai live action productions

Kamen Rider World

ZO and J, with Berry

ZO and J, with Berry.

Later, J teamed up with Kamen Rider ZO. The two riders fought a gang of five revived monsters led by Shadow Moon: Sai Mutant, Cyborg Soldier Lv. 2, Agito, Garai, and Zu. Berry witnessed Shadow Moon's plot and is attacked by the mutants. Masato and his sister Ayumi stumble onto an injured Berry by chance and are chased by the revived mutant army as a result.

However, they are saved by the sudden arrival of Kamen Rider ZO on his ZO Bringer motorcycle, who thwarts off the monsters into a nearby abandoned warehouse. ZO is suddenly assisted by Kamen Rider J, who arrives into the warehouse on his J Crosser bike. The five mutants are defeated by the combined forces of the new Double Riders. The two are then challenged by Shadow Moon, who enlarges himself into giant proportions. J grows into giant size as well and fights off Shadow Moon by himself. Shadow Moon is defeated and peace returns to the day. Kamen Rider World

All Riders vs. Dai-Shocker

He appeared in Jumbo form at the end of the battle between the Kamen Riders and Dai-Shocker, being brought in by Diend as "a treasure he'd been saving" to fight King Dark. Quickly knocked back, Diend used the Final FormRide: Decade card to turn Decade into a giant Decadriver that attached onto J, turning him into a giant Decade Complete Form. He defeated King Dark with the Final KamenAttackFormRide card, kicking through giant cards of all the primary Riders before hitting King Dark. He apparently left before the other Riders, not appearing in the crowd that walked away through the dimensional rift. Kamen Rider Decade: All Riders vs. Dai-Shocker

Decade: Final Chapter

He fought Tsukasa (Kamen Rider Decade Violent Emotion) in Jumbo form, but was defeated when Decade used The Side Basshar & G4's Gigant Kamen Ride Cards bombarding him with a barrage of missiles and sealed him in a Kamen Ride Card. J was depicted as slow moving in Jumbo Formation and unable to land a hit against the card-wielding Kamen Rider. Kamen Rider × Kamen Rider W & Decade: Movie War 2010

Let's Go Kamen Riders

J (Let's Go Kamen Riders)

J as seen in Let's Go Kamen Riders.

A mishap caused by the Greeed Ankh unintentionally altered the timeline which enabled Shocker to utilize a Cell Medal to create the Shocker Greeed which defeated the Double Riders and seemingly erased the legacy of the Kamen Riders from history. In 2011, after Kamen Rider New Den-O's attempt to repair the damage, he along with Kamen Rider OOO and M-Ankh awaited execution. However, it was revealed the Double Riders had their brainwashing removed by a Shocker scientist.

The Double Riders joined with New Den-O and OOO to fight Shocker's forces, but were eventually defeated. When the order was given to kill everyone, V3 suddenly appeared, asserting that there were more than four riders. V3 was soon followed by all the other revived riders that came after him, including J, as even though Rider history was changed, the people's memories haven't changed.

After the riders were united, they faced off against Shocker's Great Leader. Later, when joined by a force of extra riders, J and all the other riders got on their motorcycles and performed the "All Rider Break", ramming into the Rock Great Leader and defeating it once and for all. OOO, Den-O, All Riders: Let's Go Kamen Riders

Super Hero Taisen

14 Showa KR,9 Heisei Rider & 1 Neo-Heisei Rider(with Accel)

J was among the Kamen Riders caught up in the 'Super Hero Taisen' incident. He was presumably sent to the dimensional rift, under the pretense of being defeated, by Captain Marvelous while he was apparently hunting the Riders. When his and Tsukasa's ruse was revealed, J and the other Riders appeared through the dimensional wall. J then fought alongside all the other Kamen Riders and Super Sentai against Dai-Shocker and Dai-Zangyack's Shocker-Zangyack Alliance. Kamen Rider × Super Sentai: Super Hero Taisen

Kamen Rider Taisen

J vs gaim suika

J vs Gaim Suika Arms

J, in Jumbo Formation was seen fighting Fourze in Rocket States after he defeated Skyrider, and defeats the space Rider with a Jumbo Rider Punch when the latter tried to hit him with a Rider Double Rocket Drill Kick. After Fourze is defeated, he would later engage Gaim in Orange Arms, who then assumed Suika Arms Gyro Mode as he jumped off his shoulder after running up the enlarged Rider to properly fight J, with the smaller Rider proved to be more than a perfect counter to J. J was then defeated by Yoroi Mode skewering his Suika Sojinto hard into his chest, turning him into a Lockseed. Heisei Rider vs. Showa Rider: Kamen Rider Taisen feat. Super Sentai

Super Hero Taisen GP Kamen Rider 3Icon-crosswiki


Due to the timeline alteration caused by Shocker, J became one of the brainwashed Riders in that timeline, donning the name of Shocker Rider J. Later on, he aided the other Riders to combat Shocker after he, and the other Riders, were released from being brainwashed by the revived Double Riders.

J appears in Jumbo Formation to fight the Rider Robo, but is erased from history by the Robo's in-built History Modifying Machine. He is restored along with all the other Riders when the Rider Robo is destroyed by ShurikenjinIcon-crosswiki Tridoron. Super Hero Taisen GP: Kamen Rider 3


Kamen Rider J
Kamen Rider J

Kamen Rider J

Kamen Rider J's primary form. In this form, Kamen Rider J has the ability to execute the J-Kick.

Appearances: Kamen Rider J, Kamen Rider World, Let's Go Kamen Riders, Super Hero Taisen, Kamen Rider Taisen

Jumbo Formation

Giant Kamen Rider J

By harnessing the lifeforce from the surrounding life forms, Kamen Rider J can grow into a giant size at 40 meters tall (the largest size he has used) to fight against larger opponents. In this form, Kamen Rider J has the ability to execute the Jumbo Rider Kick. This form`s exact power is unknown, but is presumably comparable with even Ultraman as he knocked a creature as heavy as Mother Fog away and withstood a beam that was hinted to have made the dinosaurs extinct without being too seriously injured.

Appearances: Kamen Rider J, Kamen Rider World, All Riders vs. Dai-Shocker, Decade: The Last Story, Kamen Rider Taisen, Super Hero Taisen GP




Legend Rider Devices

Kamen Ride J

Kamen Ride J

Kamen Ride J (カメンライドJ Kamen Raido Jei) is the Kamen Ride Card which contains the power of Kamen Rider J. Used by Diend to summon Kamen Rider J in Jumbo Formation. Used in the World of Decade to fight King Dark.

In All Riders vs. Dai-Shocker, Decade Complete Form Jumbo Formation performed the Final Dimension Kick, a variation of the Dimension Kick, transforming the Shōwa Riders, including J, and Heisei Riders into Kamen Ride cards for Decade to travel through as opposed to Final Attack Ride cards before hitting the target.

In Kamen Rider × Kamen Rider W & Decade: Movie War 2010, Decade acquires Kamen Ride Cards for all of the Kamen Riders he defeats, including J, Skyrider, and Super-1.

J LockSeed

J Lockseed

Kamen Rider J Lockseed (仮面ライダーJロックシード Kamen Raidā Jei Rokkushīdo): A Lockseed bearing the likeness of Kamen Rider J, created when J was defeated in the battle between the Showa Riders and Heisei Riders. Heisei Rider vs. Showa Rider: Kamen Rider Taisen feat. Super Sentai The core image depicts J's waist while the lid backside image depicts Berry. When inserted into a Sengoku Driver or when channeled through the Showa Rider Lockseed, it would allow an Armored Rider to assume J Arms (Jアームズ Jei Āmuzu). It is styled for Gaim, Kurokage, Bujin Gaim, and Kamuro in the toyline.

  • Transformation: J Arms: Shingeki Jumbo Formation!
    • Squash: J-Kick (Jキック Jei Kikku)
    • Au Lait: J-Crosser (ジェイクロッサー Jei Kurossā)
    • Sparking: Jumbo Rider Kick (ジャンボライダーキック Janbo Raidā Kikku)

Other Appearances

Although Yūta Mochizuki has never returned to portray the character Kouji Segawa, the "Kamen Rider J" character has appeared in later Kamen Rider/Super Sentai live action productions.

Kakuranger Stage Show at Super Hero Korakuen Yuenchi

In a stage show where the KakurangersIcon-crosswiki are seen fighting their usual foes, The Bandora GangIcon-crosswiki, the Gorma TribeIcon-crosswiki, and Fog show up and they end up defeating them. Kamen Rider J, RyuuIcon-crosswiki, HououIcon-crosswiki, TyrannoIcon-crosswiki & DragonRangerIcon-crosswiki then arrive to assist the Kakurangers.

Video Games

  • Kamen Rider J is a playable character in the 2011 Nintendo DS video game All Kamen Rider: Rider Generation and Rider Generation 2 for the Nintendo DS and Sony PSP.
Screen Shot 2016-10-06 at 8.57.01 PM

Jumbo Formation in All Kamen Rider: Rider Revolution

  • He is also playable in All Kamen Rider: Rider Revolution, as is his Jumbo Formation mode, which make this the first console game to have Jumbo Formation be playable.

Kamen Rider Battle: Ganbaride

To be added

Behind the scenes


Kouji Segawa was portrayed by Yūta Mochizuki (望月 祐多 Mochizuki Yūta). As Kamen Rider J, his suit actor was Jiro Okamoto (岡元 次郎 Okamoto Jirō).

Rider No.

As the leading Rider protagonist of Kamen Rider J, Kouji Segawa (Kamen Rider J) is labeled Kamen Rider #15 (仮面ライダー15号 Kamen Raidā Jūgogō) and Showa Rider #15 (昭和ライダー15号 Shōwa Raidā Jūgogō). Quiz! Decade Countdown!!


  • Yuta Mochizuki, who played Kouji Segawa, also played Yamato Tribe Prince GekiIcon-crosswiki, one of the protagonists from Kyōryū Sentai ZyurangerIcon-crosswiki.
  • Interestingly, Kamen Rider J closely resembles Kamen Rider ZO.
    • This is because the producer of the two films wanted the two to be the new Double Riders.
      • This was mentioned by Kamen Rider ZO himself in the 4th episode of the Lets Go Kamen Rider Net Movies, where he complained that everyone mistakes him for J when they are in a scene together.
  • Kouji is alternatively referred by the Earth Spirits and Berry in the film as the J Power Warrior.
  • In the film, Kouji had a habitual quirk of quickly doing a hand motion that makes the shape of a "J" with his fingers and thumb before executing a Rider Punch or Rider Kick finisher.
  • Kamen Rider J's ability, Jumbo Formation closely resembles Ultraman, the difference is when Ultraman changes he automatically transforms into a giant. Another difference is Ultraman is powered by intense light and can only fight for a short period of time on Earth, while J is powered by the life energy of the Earth and can fight for as long as he wants in Jumbo Formation.
  • Despite being a powerful Rider in his own right, J is frequently defeated in crossover films. There is no explanation at this time as to why writers have this attitude towards the character (Although it may simply be due to avoiding the difficulties of including a giant character in a movie where the rest of the characters are human size).
  • Kamen Rider J is considered by fans to be the last of the Showa Era Riders due to Shotaro Ishinomori's death in 1998, despite the official Showa Era ending in 1989 with the death of Emperor Hirohito. Toei eventually adopted this same classification in the 2014 film Heisei Rider vs. Showa Rider: Kamen Rider Taisen feat. Super Sentai out of respect to the creator of the franchise as well as the fans. All future Riders would be classified as Heisei Riders due to them being created without Ishinomori's involvement.


Main article: Kouji Segawa/Appearances

See also


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