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Icon-w.png This article is about a villain in Kamen Rider W.

Saeko Sonozaki (園咲 冴子, Sonozaki Saeko) was the eldest child of the Sonozaki Family, wife of Kirihiko Sudo, owner of Digal Corporation and later head of Museum. Saeko was one of the major antagonists in Kamen Rider W, first appearing as an antagonist but later had a more neutral role.


While Sokichi Narumi and Shotaro Hidari infiltrated a top secret installation, seeking the "Chosen Child," whose powers were being used for evil, the alarm sounds and Saeko in her Taboo Dopant form along several Masquerade Dopants fight Sokichi who transforms into Kamen Rider Skull. Sokichi's fedora is damaged by her during the fight. She later appears again as the Taboo Dopant shortly after Philip is rescued from the central chamber of the Gaia Tower and Sokichi had been shot to death. When Shotaro and Philip transforms into Kamen Rider Double for the first time, she flees just before the building explodes. (ep. 1, Movie War 2010)

One year later, Saeko is seen at Digal Corporation and working with her husband Kirihiko Sudo, distributing the Gaia Memories and becoming the Taboo Dopant to combat Kamen Rider Double. Later when she kills Kirihiko and begins regularly visiting Isaka to improve herself, she forms a partnership with him to overthrow her father and tries to kill Wakana Sonozaki for not taking her side but the Smilodon Dopant drives her away. However, Isaka is defeated by Kamen Rider AccelTrial causing her coup to fail and she ends up on the lam. Saeko is hunted down by the Smilodon Dopant, who takes the Taboo Memory and leaves her for dead. She is then saved by Jun Kazu who offers his support in her scheme to take control of the Museum. After infiltrating the Digal Corporation, now with Wakana as its head, she obtains the Nasca Memory and then uses an L.C.O.G on herself instead of using the Memory with a Driver. Without inhibitions posed by a Driver, Saeko is able to use the Gaia Memory in its Level 3 state to become the R Nasca Dopant to overpower her sister. However, when Wakana evolves to Claydoll Xtreme, which Saeko proves to be utterly powerless against, she is forced to go after other options to make herself more powerful, such as the Jewel Memory, before the Nasca Memory is destroyed in a confrontation with Claydoll Xtreme. Later, after her father's death, Saeko is disillusioned until she learns of Wakana's survival and regains the Taboo Memory from Kazu after he announces that she has become the head of the Museum. However, no longer having a reason to prove herself with her father dead, Saeko fights Kazu in order to save her sister. As a result, the Taboo Dopant sacrifices herself to hold off the Utopia Dopant to give Wakana time to run away, resulting in Saeko's death as she finally admits the irony of her last moments in her final breath. She later appeared with the rest of her family to say goodbye to Philip while showing that she reconciled with Wakana whom she comforted.


Her father, Ryubei Sonozaki strictly raised Saeko to believe that their family is superior to all others and that they are destined to rule the world. This loveless upbringing caused her to grow up secretly hating her father, often taking the resulting rage out on her younger sister Wakana Sonozaki, serving as fuel for her own ulterior motives of taking over the Museum to prove herself to her father to be its ideal successor. She also has a tendency to kill her boyfriends if they do not live up to her expectations. Although Saeko initially spares Kirihiko Sudo due to his capabilities, even marrying him and letting him be a part of the Sonozaki Family, she kills him when he threatens the Museum's livelihood. She has no problems executing Kirihiko as she had never loved him. Later, she pay regular visits to Dr. Shinkuro Isaka to improve her Dopant form and focus on her plans for the Museum. After he is almost defeated by the Kamen Riders, she begins to show that she cares for Isaka's well-being, which is likely to be genuine attraction to the doctor. 

Video Game appearances

Kamen Rider Battle Ganbaride

Taboo Dopant card

The Taboo Dopant appears as an of the many Bosses in this video game with other Kamen Riders and Monsters in Kamen Rider Gabanrider.

Kamen Rider Travelers Record

The Taboo Dopant and the Nazca Dopant facing Philip, Kamen Rider Accel, and Kamen Rider Fourze in Kamen Rider Travelers Record.

The Taboo Dopant appears in the video game Kamen Rider Travelers Record.

Kamen Rider: Battride War Genesis

Taboo Dopant in Kamen Rider: Battride War Genesis

The Taboo/Nasca Dopant appears as a boss in Kamen Rider: Battride War Genesis

Kamen Rider Break Joker

Saejo as The Taboo and R Nasca Dopant appears as a playable character with other Riders and monsters in Kamen Rider Break Joker.

Kamen Rider: memory of heroez


Other Game appearances

Masked Rider Expansion

Taboo Dopant Masked Rider Expansion card

The Taboo Dopant as a playable character in this trading card game with other Kamen Rider Kamen Rider Heisei-Era, Showa-Era, super sentai, Metal Heroes, and other Heroes.

Battle Spirits

Taboo and R Nasca Dopant appears with other Kamen Riders and Monsters in Battle Spirits.

Dopant Forms

As a member of the Sonozaki Family, Saeko owned a Gaia Driver and a golden Gaia Memory, Taboo, but when they are taken from her by the Smilodon Dopant, she uses her ex-husband's Nasca Memory in place of them until it is destroyed. She then regained her original Taboo Memory from Kazu which she used against him, leading to her death.

Taboo Dopant

Taboo Dopant

Main article: Taboo Dopant
―Transformation announcement[src]
  • Height: 200cm
  • Weight: 72kg

The Taboo Dopant (タブー・ドーパント, Tabū Dōpanto) is Saeko's first Dopant form accessed through the Gaia Driver and Taboo Memory. In this form she has the appearance of a rag doll and gains the ability to fly and generate deadly bombs of intensely hot light. It was further increased in power due to some modifications to her Gaia Driver by Isaka, to the extent of being unaffected by certain Dopant powers such as that of the Yesterday Dopant. This form is lost after Mick as the Smilodon Dopant takes her equipment away and nearly kills her. She regained the Taboo Memory after Kazu presented it to her, the memory was destroyed by the Utopia Dopant in a fight against him.

Appearances: W Episodes 1, 2, 4, 10, 13, 16, 18, 25-26, 34, 36-37, 48

―Transformation announcement[src]

The Nasca Dopant (ナスカ・ドーパント, Nasuka Dōpanto) is Saeko's second Dopant form accessed through the Nasca Memory which was first used by her late husband, Kirihiko Sudo. Unlike her transformation into the Taboo Dopant, Saeko used the L.C.O.G on herself, creating a Living Connector to use the memory instead of a Gaia Driver which limited the powers of the Gaia Memories. The Nasca Dopant is armed with the Nasca Blade (ナスカブレード, Nasuka Burēdo) with the powers of flight from the Nasca Wings (ナスカウイング, Nasuka Uingu).

Nasca Dopant

Nasca Dopant

"Blue Nasca" (青いナスカ, Aoi Nasuka) is the name given to the default form of the Nasca Dopant which was accessed by Kirihiko Sudo. This form briefly appears during Saeko's transformation into the Nasca Dopant before evolving to her advanced R Nasca form.

Appearances: W Episodes 39-40

R Nasca Dopant

R Nasca Dopant

  • Height: 198cm
  • Weight: 92kg

The R Nasca Dopant (Rナスカ・ドーパント, R Nasuka Dōpanto, "R" for both "Red" and "Revenge") is the evolved form on the Nasca Dopant which is accessed by Saeko. Unlike Kirihiko's form which is blue with red markings, Saeko's is an orangish-red and possesses greater speed and power due to being Level 3. The R in the name stands for both Red (the forms color) and Revenge (Saeko's feeling towards her father and sister). But when Wakana evolves into Claydoll Xtreme Saeko went after other plans to empower herself further such as the Jewel Dopant. However the Nasca Memory was destroyed in a fight against Claydoll Xtreme.

Appearances: W Episodes 39-40, 46



Behind the scenes


Saeko Sonozaki is portrayed by Ami Namai (生井 亜実, Namai Ami), As Taboo Dopant, her suit actor is Yuuki Ono (小野 友紀 , Ono Yuuki).

Concept Art

Taboo Dopant and Nasca Dopant were designed by Katsuya Terada (寺田 克也, Terada Katsuya).


Ami Namai assumed the garb of Saeko Sonozaki in 2020 to promote the Futo Tantei manga.[1]

  • R Nasca Dopant is a repainted version from the orginial Nasca Dopant.


External Links

Icon-w.png Kamen Rider W
Narumi Detective Office
Shotaro Hidari - Philip - Akiko Narumi - Sokichi Narumi† - Tokime
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The Sonozaki Family: Terror - Claydoll - Taboo/R Nasca - Nasca - Smilodon - Masquerade Dopants
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