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

"You want me... to count my sins...? Then, is it a sin... to love...?"
―Jun Kazu's last words before he disappears[src]

Jun Kazu (加頭 順 Kazu Jun) is the main antagonist of Kamen Rider W's last story arc. He was a researcher of Foundation X wearing a lab coat at almost all times. He also appeared in Kamen Rider W Returns: Eternal, a prequel to the main TV series.

Initially taking the form of the incomplete Kamen Rider Eternal (仮面ライダーエターナル Kamen Raidā Etānaru), he later became the Utopia Dopant (ユートピア・ドーパント Yūtopia Dōpanto).



Jun as the Utopia Dopant before his death.

Prior to his introduction, Kazu was originally Doctor Prospect's liason for the Foundation giving him the psychic abilities of the Quarks. He was also in possession of the T1 Eternal Memory and a Memory Driver but he was incompatible with the imperfect Gaia Memory and could only assume the Red Flare form of Kamen Rider Eternal. It was then he was given the more compatible Utopia Memory and Gaia Driver to become the Utopia Dopant. In a fight with Katsumi Daido as Eternal Blue Flare, Kazu was killed and his body was then preserved so that he could be revived as a Necro-Over.


Kazu first appears to Ryubee Sonozaki when Ryubee tells him that with his daughter, Wakana Sonozaki, the groups funding they gave to the Museum will be well worth it. After Saeko is left for dead by the Smilodon Dopant, Kazu saves her out of love and offers to help her but she turns him down. He then witnesses Saeko use the powers of the Level 3 R Nasca Dopant and learns about her sister's role in the way she was raised. It is only after Wakana evolves into Claydoll Xtreme that Saeko accepts Kazu's advice. In his first appearances Kazu holds a briefcase containing the T2 Gaia Memories at all times until he gives them to Tabata to take to their headquarters.

After Ryubee's death, he rescued Wakana from the burning Sonozaki Estate, and with Saeko, he plans to resume the Gaia Impact. However, Wakana's comatose state forces Kazu to wait until her power resurfaces. He then reveals himself to the Kamen Riders as the Utopia Dopant and overwhelms them. Upon discovering that Wakana's consciousness is connected to Philip, and that his anguish rises her compatibility with the Claydoll Memory fused into her body, he attempts to force out Philip's anguish to awaken Wakana and complete the Gaia Impact to the extent of attacking everyone close to him.

After Saeko betrays him, Kazu is revealed to be a Necro-Over evident by his inability to be burned or destroyed by the Taboo Dopant's light ball attacks. After attacking and when Wakana wakes up, he gives Saeko one last chance to work together with him only to be attacked again and reluctantly kills her. He is then approached by Shotaro, who without transforming and with the Memory Gadgets, restrains the Utopia Dopant, saves Wakana, and destroys the facility before the Gaia Impact can initiate. The Utopia Dopant however survived, infuriated at Shotaro and then goes after him. When Philip arrives, he and Shotaro transform into Kamen Rider Double CycloneJokerXtreme, and fight against the already badly hurt Dopant and they further weaken him with Philip's final feelings. Enraged, Kazu proceeds to destroy them, but fortunately, Double was able to defeat him with the Double Prism Xtreme Maximum Drive. Dissolving into dust, Kazu tries to activate the memory again, only for him to drop it and it shatters. He then asks if it was a crime to love and fades to nothingness.

Kamen Rider Zi-O

Five Last Bosses summoned.png

An iteration of Utopia Dopant, along with N-Daguva-Zeba, Kamen Rider Evol, Sagittarius Zodiarts, and Gamedeus, appears to be summoned by Swartz/Another Decade. He was defeated by Ohma Zi-O instantly.2019: Apocalypse

Net Movies Appearance

Jun Kazu also makes a non-canon appearance in the Kamen Rider W Net-Movies. Here Kazu is a guest in Kirihiko's talkshow. Kazu is insulting Kirihiko with the fact he wasn't a great addition to Museum. He also tells Kirihiko he is Museum's sponsor. Kirihiko confronts Kazu by showing clips of his weird habit of dropping things. Kazu responds to this by dropping various objects on Kirihiko. He then takes his leave while telling Kirihiko that he won't be abandoned by Saeko like Kirihiko was.

Video Game Appearances

Kamen Rider Buttobasoul

Kamen Rider Eternal (Red Flare) medal

Kamen Rider Eternal (Red Flare) is a playable character in Kamen Rider Buttobasoul.

Other Game Appearances

Battle Spirits

Utopia Dopant Battle Spirits card

Jun Kazu as Utopia Dopant appears with other Kamen Riders and Monsters in Battle Spirits.


Kazu most of the time appears cold and emotionless and has a strange habit of dropping whatever he is holding whenever he is shocked. He was not completely emotionless as he saved Saeko Sonozaki from near death out of love and was willing to tell her things about his organization, such as the T2 Gaia Memories. He has also shown an evil smile when resuming the Gaia Impact. He shows emotion only when things do not go his way such as the failure of the Gaia Impact displaying anger at Shotaro Hidari for interfering. He also seems to be clueless as he thought that his crime was to love when it was because of the many crimes he did and was going to commit.


Utopia Dopant

Utopia Dopant

Main article: Utopia Dopant
―Transformation announcement[src]
  • Height: 222 cm
  • Weight: 111 kg

When the Kamen Riders came to save Wakana, Kazu reveals his ownership of the golden Utopia Gaia Memory as well as a Gaia Driver he received as a side payment from the Museum in order to become the seemingly omnipotent and powerful Utopia Dopant possessing more powers than the extremely enhanced Weather Dopant, his comparability with the memory is 98%. So powerful, that just transforming into his Dopant form causes unheld-in-place objects to levitate and get pushed away when he transforms. His reality-bending powers result from the memory's ability to grant wishes and absorbing the aspirations and ambitions of others. The most seen of his powers is telekinesis which he uses for bringing people and things to him, repelling attacks from enemies, levitating objects, and causing great pain onto others. It is revealed in Kamen Rider Eternal, that most of his telekinesis and pyrokinesis, are due to him being a Quark.

The Utopia Dopant is armed with a cane as his weapon. He also demonstrated releasing fire from his hands, with strength powerful enough to tear apart a street causing steam to erupt then disappear, summoning a tornado with a small thunderstorm, move at high speeds, stealing some of people's life force and adding it to his power, reverting transformed people into base or human forms, causing people or things to combust, and the ability to make people's faces disappear and putting them in a comatose state. During the final battle against Kamen Rider Double, Utopia Dopant has demonstrated a technique of his own Rider Kick similar to the Double CycloneJokerXtreme's Double Xtreme Maximum Drive.

Kamen Rider Eternal (Red Flare)

Kamen Rider Eternal Red Flare

―Transformation announcement[src]

Red Flare is Eternal's weaker/incomplete form. This form of Eternal was accessed by Jun Kazu using the standard Eternal Memory, but due to incompatibility with the memory, he could only access the Red Flare form. Unlike it's Blue Flare counterpart, it lacks the extra Memory Slots, and Eternal Robe, and the flame designs on the arms and leg bands are red instead of blue, true to this form's name.

This form is exclusive to Kamen Rider W Returns: Kamen Rider Eternal


Behind the scenes


Jun Kazu is portrayed by Gong Teyu (コン・テユ Kon Teyu).

As the Utopia Dopant and Kamen Rider Eternal Red Flare, his suit actor is Jun Watanabe (渡辺 淳 Watanabe Jun).




Narumi Detective Agency
Shotaro Hidari - Philip - Akiko Narumi - Sokichi Narumi† - Tokime
Double Driver - Accel Driver - Lost Driver - Gaia Memories - Memory Gadgets - Fang Memory - Xtreme Memory - Trial Memory - Gaia Memory Enhancing Adapter - Metal Shaft - Trigger Magnum - Engine Blade - Skull Magnum - Prism Bicker - Eternal Edge - RevolGarry - HardBoilder - Gunner A - Shroud Magnum - SkullBoilder - SkullGarry
The Fuuto Irregulars
Santa-chan - Watcherman- Queen & Elizabeth - Isamu Bito
Futo Police Department
Ryu Terui - Mikio Jinno - Shun Makura
Museum and the Dopants
Foundation X
The Sonozaki Family: Terror - Claydoll - Taboo/R Nasca - Nasca - Smilodon - Masquerade Dopants
Dopants: Magma Dopant - T-Rex Dopant - Money Dopant - Anomalocaris Dopant - Cockroach Dopant - Sweets Dopant - Virus Dopant - Violence Dopant - Arms Dopant - Bird Dopant - Ice Age Dopant - Triceratops Dopant - Liar Dopant - Puppeteer Dopant - Invisible Dopant - Nightmare Dopant - Beast Dopant - Zone Dopant - Yesterday Dopant - Quetzalcoatlus Dopant - Gene Dopant - Jewel Dopant - Old Dopant - Utopia Dopant - Energy Dopant
Movie Exclusive Villains: Dummy Dopant - Heat Dopant - Trigger Dopant - Metal Dopant - Luna Dopant - Cyclone Dopant - Bat Dopant - Spider Dopant - Kamen Rider Eternal - Commander Dopant - Eyes Dopant
Manga Exclusive Villains (Futo Detective): Road Dopant - Aurora Dopant - Meganeura Dopant -Brachiosaurus Dopant - Scream Dopant - Alcohol Dopant - Puzzle Dopant - Reactor Dopant - Antlion Dopant - Owl Dopant - Trash Dopant - Caracal Dopant - Toadstool Dopant
Katsumi Daido - Maria S. Cranberry - Reika Hanehara - Kyosui Izumi - Gozo Domoto - Ken Ashihara
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