|This article is about a/an actor in Kamen Rider V3.|
Takehisa Yamaguchi (山口 豪久 Yamaguchi Takehisa), born as Tomoyuki Yamaguchi (山口 智之 Yamaguchi Tomoyuki) (January 25 1945 - April 6 1986), played Joji Yuki/Riderman in Kamen Rider V3, Riderman being the partner of Kamen Rider V3. He also acted as suit actor for Riderman. He was credited as Satoru Yamaguchi (山口 暁 Yamaguchi Satoru). He was also known as Akira Yamaguchi (山口 あきら Yamaguchi Akira).
Yamaguchi is notably the earliest-born actor to portray a Kamen Rider, with his birth preceeding that of Hiroshi Fujioka by over one year, also making him the only such actor to have been born prior to the end of World War II.
Takehisa Yamaguchi only returned in one episode of Kamen Rider (Skyrider). In the other four episodes where Riderman appeared, he was portrayed by suit actor Junichi Iwai (岩井 潤一 Iwai Jun'ichi) alongside assorted voice actors.
In 1984, he reprised his role alongside Hiroshi Miyauchi (Kamen Rider V3) and Shunsuke Takasugi (Kamen Rider Super-1) in Birth of the 10th! Kamen Riders All Together!! (1984), which introduced Kamen Rider ZX.
Takehisa Yamaguchi passed away from liver cancer on April 6 1986, at the age of 41. He was the first actor who played a Kamen Rider to die. After his death, Riderman would be portrayed by several voice actors and suit actors in his later appearances.