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

Shinkuro Isaka (井坂 深紅郎 Isaka Shinkurō), who was able to become the Weather Dopant (ウェザー・ドーパント Wezā Dōpanto) was a minor antagonist in middle story part of Kamen Rider W, and the archenemesis of Kamen Rider Accel.


He was the 42 year old head physician at the Isaka Medical Clinic (井坂内科医院 Isaka Naika Iin). Ten years ago, finding no meaning in his life, he encountered Ryubee Sonozaki attacking a group of people as the Terror Dopant. This brought maddening joy to the doctor and he made a point to get the Terror Memory for himself, experimenting on himself with numerous Gaia Memories with various Living Connectors on his body before Shroud gave him the Weather Memory in the hope that he would be powerful enough to eliminate Ryubee.

He originally tested these abilities in a series of freezing, electrocution and drowning murders which included Ryu Terui's family, to whom he was only known as the "man with the W Memory (W(ダブリュー)のメモリを持つ男 Daburyū no Memori o motsu otoko)". Isaka does not use a Gaia Driver, as he feels he doesn't need the protection provided, as he was unaffected by their corruption due to him being already intensely psychotic, and the limits imposed on the power of Gaia Memories due to the Driver annoy him greatly. The Weather Dopant can also withstand Maximum Drives, as he has augmented the Weather Memory with other Gaia Memories' powers. This skill and his knowledge of Dopant physiology makes him an ally to the Museum. Due to his experiments, he burns a lot of calories and eats enough in one sitting for several people as a result. He modifies Wakana Sonozaki's Gaia Driver to maximize her potential as the Claydoll Dopant under Saeko's request.

After his identity was discovered during his failed attempt to add the Invisible Memory to his arsenal in episode 27, Isaka takes refuge in the Sonozaki estate where he convinces Saeko to take out her father so she can control the Museum and he can get the Terror Memory. Though he originally sees Saeko as merely one of his pawns and research material, he admits to having developed feelings for her. During his attempt to absorb the Quetzalcoatlus Memory, the Weather Dopant was finally defeated by Kamen Rider AccelTrial's Machine Gun Spike Maximum Drive, shattering the Weather Memory. Shortly afterwards, Isaka's excessive use of Gaia Memories causes his body to become covered in Living Connectors that dissolve him away into nothingness as he tells the Kamen Riders that Shroud will be their end.

Shroud later expressed regret to Ryu for giving Isaka the Weather Memory, having no idea of what a monster he would become with the Memory.

Super Hero Taisen


However he is revived in Super Hero Taisen as a member of Dai-Shocker, who teamed up with Dai-Zangyack and fought against the army of Kamen Riders and Super Sentai. He is seen fighting Red Flash in the first aerial attack scene along with Me-Garima-Ba, and with DynaBlue and GingaRed in the next scene. In a scene of the trailer, he was seen fighting his enemies Kamen Rider Double and Accel.

Super Hero Taisen GP

The Shocker army.

Through an alteration to history rewritten by Shocker's History Modifying Machine, the Weather Dopant is among the many monsters that serve the evil organization that rules the world in this alternate timeline created by Kamen Rider 3's assassination of the Double Riders in 1973. During the final battle against the Kamen Riders, the Weather Dopant is destroyed by V3's V3 Kick. Super Hero Taisen GP: Kamen Rider 3

Video Game appearances

All Kamen Rider: Rider Generation

Weather Dopant in All Kamen Rider: Rider Generation.

The Weather Dopant appears as a monster in the video game All Kamen Rider: Rider Generation.

Kamen Rider: Battride War

The Weather Dopant appears as a boss in the video game Kamen Rider: Battride War. Weather Dopant is able to create tornadoes that are quite difficult to dodge. He can also spray a freezing mist and can shoot lightning. Just like El of the Water, he tends to use environmental obstacles like tornadoes and lightning while the player advances through the game. He does not have much of a weakness, so it's quite hard to battle the Dopant.

Kamen Rider Batton-Line

Accel vs. Weather Dopant in Batton-Line.

A scenario featuring the rivalry of Kamen Rider Accel and Weather Dopant will be included in the online PC game, Kamen Rider Batton-Line.

Dopant Form

Main article: Weather Dopant

Weather Dopant

―Transformation announcement[src]
  • Height: 248 cm
  • Weight: 115 kg

By using the Weather Memory, Isaka is able to transform into the Weather Dopant (ウェザー・ドーパント Wezā Dōpanto). As Weather Dopant, he was armed with the whip-like Weather Mine (ウェザーマイン Wezā Main) and had control over the elements (which can augmented into the Weather Mine): intense sunlight, heavy rain, lightning, tornadoes, and freezing snow. He originally tested these abilities in a series of murders which include Ryu Terui's family, to whom he was only known as the man with the W Memory (W(ダブリュー)のメモリを持つ男 Daburyū no Memori o motsu otoko). Isaka does not use a Gaia Driver, as he feels it only limits the power of Gaia Memories, and he is unaffected by their corruption as he was already intensely psychotic. The Weather Dopant can also withstand Maximum Drives, as he has augmented the Weather Memory with other Gaia Memories' powers. This skill and his knowledge of Dopant physiology makes him an invaluable ally to the Museum.

Appearances: W Episodes 27-36

Behind the scenes


Shinkuro Isaka was portrayed by the late Tomoyuki Dan (檀 臣幸 Dan Tomoyuki).[1], who passed away on October 10, 2013, at age 50, only a few months after reprising his role as the Weather Dopant in the video game Kamen Rider: Battride War.



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