|Born:||May 23, 1965|
|Occupation:||Voice actor, Actor|
|Years active:||1985 – Present|
|Spouse:||Unknown (currently married)|
Kappei Yamaguchi started as an actor in 1985 while he began his career as a voice actor and stage actor in 1988. He is most known for his roles as Usopp in One Piece and Shinichi Kudo and Kaito Kid in Detective Conan.
Kappei Yamaguchi has married and he has a son.
- Ultraman Super Fighter Legends - voice of Astra
- Ranma 1/2 - voice of Ranma Saotome
- One Piece - voice of Usopp and Eyelashes
- Keroro Gunso - voice of Tororo
- Death Note - voice of L Lawliet
- Inuyasha - voice of Inuyasha
- Miracle Girls - voice of Jackson Neil
- Kiki's Delivery Service - voice of Tombo
- Kyatto Ninden Teyandee - voice of Yattaro
- Bugs Bunny (dub voice)
- Detective Conan - voices of Kaitō Kid and Shinichi Kudo
- Magic Kaito - voice of Kaito Kuroba / Kaito Kid
- Teenage Mutant Ninja Turtles (2012) - Michelangelo (dub voice)
- Yu Yu Hakusho - voice of Jin
- Sometimes, his name is mistaked as Katsuhei Yamaguchi or Shōhei Yamaguchi.
- Kappei uses the stage name Ushiku Kyōya (牛久 京也 Kyōya Ushiku) when he appears in many games have adult content (eroge).
- When Kappei Yamaguchi went to see the filming of "Boyce Lager" (7 episodes) with his family, he had appeared as an extra with a family role that came to see the hero show in the play in the play, and his son, who was held by Kappei, asked "What is a voice actor? " In addition, when Kappei gave his son's name under the name of a fan letter at the talk part of the ninth story of "Beast Worth Metals", he said that he was angry that "I am ashamed".