Kouji Segawa

Kouji Segawa (瀬川 耕司) is Kamen Rider J (仮面ライダー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.

Kamen Rider World
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.

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 King Dark. 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 King Dark.

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.

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.

Super Hero Taisen
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 Taisen
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.

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 Tridoron.

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 are seen fighting their usual foes, The, the , and Fog show up and they end up defeating them. Kamen Rider J,, , &  then arrive to assist the Kakurangers.

Video Game appearances

 * 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.

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

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

Kamen Rider SD
Although J didn't 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 and.

Device

 * J-Spirit: Transformation belt

Vehicle

 * J-Crosser: J's Rider Machine

Portrayal
Kouji Segawa was portrayed by Yūta Mochizuki (望月 祐多), who previously played in the Super Sentai series, . As Kamen Rider J, his suit actor was Jiro Okamoto (岡元 次郎).
 * In Kamen Rider Decade: All Riders vs. Dai-Shocker, he was voiced by Kouta Nemoto (根本 幸多) and portrayed by suit actor Jiro Okamoto (岡元 次郎).
 * In Kamen Rider Decade: The Last Story, he was voiced again by Kouta Nemoto (根本 幸多) and portrayed by an unidentified suit actor.
 * In Heisei Rider vs. Showa Rider: Kamen Rider Taisen feat. Super Sentai, Kamen Rider J is voiced by Tetsu Inada (稲田 徹)

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) and Showa Rider #15 (昭和ライダー15号).