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Icon-j.pngThis article is about a rider in the film Kamen Rider J.

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

26 years old[note 1], Kouji Segawa is a rising nature photographer[2] who mainly deals with wildlife and natural scenery, interested in environmental issues like the pollution of mountain lakes and forests in Japan. During the investigation, 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.

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

Using his Kamen Ride Card, J was summoned by DiEnd in Jumbo Formation at the end of the battle between the Kamen Riders and Dai-Shocker to fight Kingdark. J was referred to DiEnd as "a treasure he'd been saving". 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. The battle ended using the Final KamenAttackFormRide card, kicking through giant cards of all the primary Riders and performing the Final Dimension Kick, defeating Kingdark. 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 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).jpg

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 SentaiIcon-crosswiki.png against Dai-Shocker and Dai-Zangyack's Shocker-Zangyack Alliance. Kamen Rider × Super Sentai: Super Hero Taisen

Kamen Rider Taisen

J vs Gaim Suika Arms

J, in Jumbo Formation was seen fighting Fourze in Rocketstates 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.png


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. In Jumbo Formation, J menaced the rebel Kamen Riders, Shinnosuke Tomari, Go Shijima and Kyoichiro Kuroi as they made camp overnight. As Shinnosuke made his stand, J faced down the Tridoron Type Wild only to lose his prey as Yuto Sakurai's ZeroLiner intercepted and spirited Tridoron away.

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.png Tridoron. Super Hero Taisen GP: Kamen Rider 3

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

Video Game appearances

All Kamen Rider: Rider Generation/Rider Generation 2

Kamen Rider J is a playable character in the 2011 Nintendo DS video game All Kamen Rider: Rider Generation and its sequel, Rider Generation 2 for the Nintendo DS and Sony PSP.

All Kamen Rider: Rider Revolution

Jumbo Formation in All Kamen Rider: Rider Revolution

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

Kamen Rider Battle: Ganbaride


Kamen Rider J is a playable character in Ganbaride with other Riders.

Kamen Rider Battle: Ganbarizing

Kamen Rider J card

J is among the vast majority of Kamen Riders that are available in this arcade game.

Kamen Rider SD

SD J.jpg

Although J did not show up in any Kamen Rider SD media such as manga, OVA, or video games, his SD counterpart was released as a soft vinyl figure toy in one of the SD toylines along with ShowIcon-crosswiki.png and NinjaRedIcon-crosswiki.png.


Kamen Rider J

Kamen Rider J

Rider Statistics:[3][4][5][note 2]

  • Rider Height: 194 cm
  • Rider Weight: 84 kg

Rider Senses:

  • Enemy Sensing: 5 km[4]

Ability Parameters:

Kouji changes into a grasshopper-like warrior form known as Kamen Rider J by focusing his J Power through using the J Sign (Jサイン, J Sain) hand movement. This hand gesture also allows him to draw J Power for finishers and in certain cases make his fingers and thumbs glow with red energy in the shape of a J.

J possesses some kind of a healing factor, as he was able to heal heavy damage such as gashes on his body from Agito's jaws and his arm being impaled. However, these injuries take a moderate amount of time to heal and J can become temporarily drained of energy during particularly long battles.

Kamen Rider J has the ability to execute a variety of attacks to defeat his opponents:

  • J-Kick (J-キック, Jei Kikku): J quickly makes the J Sign, touches the ground and then leaps into the air. J then brings his right leg upward before extending it in a flying kick as he is propelled forward at high speeds to hit the target. The impact of the kick then sends the enemy target flying backwards, after which they either explode or die from their injuries.
  • J-Punch (J-パンチ, Jei Panchi): J's Rider Punch. It is shown to be powerful enough to launch enemies several feet back or, in the case of Agito, break through the monster's skull.
  • J-Chop ( J-チョップ, Jei Choppu)[note 4]: J's Rider Chop.
  • J-Elbow (J-エルボー, J Elbō): A karate elbow strike attack. By raising his arm and making the J Sign, J can focus his strength into a powerful crushing elbow attack to break objects or stun his opponents.

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

Jumbo Formation

Jumbo Formation

Jumbo Formation (with Final Form Ride Decadriver.

Rider Statistics:

Jumbo Formation (ジャンフォーメーション, Janbo Fōmēshon) is an alternate form that Kamen Rider J can assume when the Earth is in grave peril. By harnessing the lifeforce energy from the surrounding life forms and spirits, Kamen Rider J can grow to a giant size at 40 meters tall to fight against larger opponents. This form's power allowed him to knock Mother Fog away and withstand its attacks without being seriously injured.

In this form, Kamen Rider J has the ability to execute the Jumbo Rider Kick (ジャン ライダーキック, Janbo Raidā Kikku), a flying Rider Kick with immense destructive force where J channels his J Power after leaping high into the air and briefly flashes in a pink aura. J then drops back down rapidly with his giant foot blazing with burning hot energy to attack the target with the force of a meteor strike.

J is also capable of performing a Jumbo Rider Punch (ジャン ライダーパンチ , Janbo Raidā Panchi), in which J delivers a punch enveloped in a blazing red fire-like energy as it makes impact.

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

Decade Complete Form Jumbo Formation

Decade Complete Form Jumbo Formation

Rider Statistics

  • Rider Height: 41 m[10]
  • Rider Weight: 894 t[10]

When Kamen Rider Diend uses a Final Form Ride card that turns Decade into the Jumbo Decadriver (ジャンボディケイドライバー, Janbo Dikeidoraibā), the larger version of the Decadriver is used by Kamen Rider J to transform into a fusion form called Complete Form Jumbo Formation (コンプリートフォーム ジャンボフォーメーション, Konpurīto Fōmu Janbo Fōmēshon). This Complete Form is identical in appearance to the regular version, except he is J's Jumbo size and he wears the Decadriver instead of the K-Touch on his belt buckle.

This form is exclusive to Kamen Rider Decade: All Riders vs. Dai-Shocker




  • Ride Booker - Decade Complete Form Jumbo's primary weapon


Legend Rider Devices

KamenRide: J

KamenRide: J (カメンライドJ, Kamenraido Jei) is the Rider 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 Kingdark.

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.

Final AttackRide: J

Final AttackRide: J (ファイナルアタックライドJ, Fainaru Attakuraido Jei)

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)

"(Digital beeping) J!"
―Activation announcement[src]

J Ridewatch (Jライドウォッチ, Jei Raidowotchi): Based on Kamen Rider J, this Ridewatch would provide access to the JArmor. It is dated 1994.

The ability provided by this Ridewatch is to grow into gigantified size.

Behind the scenes


Kouji Segawa was portrayed by Yūta Mochizuki (望月 祐多, Mochizuki Yūta), who previously played Yamato Tribe Prince Geki/TyrannoRangerIcon-crosswiki.png in the Super Sentai series, Kyoryu Sentai ZyurangerIcon-crosswiki.png. 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!!

Before this definition in the Decade net movies, J was originally referred to as the "14th remodeled soldier" (14人目の改造ソルジャー, Juuyon-ninme no kaizō sorujā) in trailers for the film, as Kamen Rider Black RX was originally seen as a form change for Black rather than a separate Rider.


  • 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, Listen Quietly! The Tragedy of the 20th Anniversary Rider!, where he complained that no one can tell him apart from J when they are in a scene together.
  • Kouji is alternatively referred to 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.
    • Oddly enough, due to the finisher names that start with the "J" letter, Kouji, while in his Rider form, only names his finishers with the start of the word "Rider" in from his film to future installments. The reason for this is unknown.
  • 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.
    • Incidentally, several years later, there would be an UltraIcon-crosswiki.png that would be powered by the light of the Earth, similar to J.
    • J's Jumbo Formation is an uncommon example of a Kyodai Hero (giant hero) being constrained by the real world square-cube law; though J is considerably stronger in his larger size, he moves much slower, and the ground can be visibly seen cracking under the weight of his body when his Jumbo Formation first materialises.
  • Shotaro Ishinomori, despite creating J, initially opposed the idea of J's superpower to grow to giant size, thus it did not make it to the final draft of the movie's script. The idea was pushed by Toei executives after the success of the Kamen Rider vs. Ultraman TV specialIcon-crosswiki.png where Kamen Rider 1 grew to Ultraman's size to help him, which proved to be a popular highlight of the special by fans. It wasn't until Ishinomori realized the film needed an exciting climax did he finally agree to put it back into the script under the condition that the ability had limited use and was "a miracle given to J by the power of the Earth"[note 6].
  • 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 in 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.


  • In the early promo shown during the Winter 1995 (January) Fox Kids affiliate meeting, J appeared in the title card instead of Kamen Rider Black RX in the airing


See also


  1. 1.0 1.1 Asahi Sonorama. (1994). "Uchusen Extra Issue - Ultrabooks 1994 Edition Strongest Monster/Hero Super Encyclopedia".
  2. Kodansha. (2013). "Definitive Edition All Kamen Riders & All Monsters Super Encyclopedia <Showa Edition>”. p. 98. ISBN 978-4-06-304836-0.
  3. 3.0 3.1 Takeshobo. (2001). Masked Rider Chronicles: A History of Cyborg Soldier's Battle. p. 214-215. ISBN 978-4812407837.
  4. 4.0 4.1 4.2 4.3 Kamen Rider Official Data/Perfect File.
  5. 5.0 5.1 Hobby Japan. (2005). S.I.C. Official Diorama Story: S.I.C. Hero Saga. Vol. 1. p. 73. ISBN 978-4894253896.
  6. 6.0 6.1 Futabasha. (2011). "Kamen Rider Super Dictionary”, supervised by: Ishimori Pro and Toei. ISBN 978-4-575-30333-9.
  7. Futabasha. (2015). "Kamen Rider: Showa's Strongest Legend:. p. 166. ISBN 978-4575308402.
  8. 8.0 8.1 Kamen Rider Battle: Ganbarizing card: BM2-055.
  9. Kodansha. (2010). All Kamen Rider: Complete Super Encyclopedia. p. 66. ISBN 978-4063048063.
  10. 10.0 10.1 Shogakukan. (2010). Masked Rider Decade: Complete Works. Second Volume. p. 50. ISBN 978-4091051301.
  11. http://www.all-rider.jp/character/index.html lists Kamen Rider J as Kouji Segawa


  1. "Super Encyclopedia 1994", p. 16.[1]
  2. "Super Dictionary 2011", p. 199.[6]
  3. 190 m according to one source[7]
  4. "Super Encyclopedia 1994", p. 17.[1]
  5. 736 t according to one source[9]
  6. "Super Dictionary 2011", p. 200.[6]


Icon-shin.png Icon-zo.png Icon-j.png The 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