Mitsuo Yamaguchi (山口 光雄 Yamaguchi Mitsuo?, May 23, 1965, Fukuoka, Japan), better known by his stage name of Kappei Yamaguchi (山口 勝平 Yamaguchi Kappei?), is a Japanese voice actor and actor from Fukuoka, affiliated with Gokū and 21st Century Fox.
He is best known for the roles of Ranma Saotome (Ranma ½), Jackson Neil (Miracle Girls), Tombo (Kiki's Delivery Service), Yattarō (Kyatto Ninden Teyandee), Inuyasha (Inuyasha), Ryuichi Sakuma (Gravitation), L (Death Note), Usopp (One Piece), Hideyoshi Soya (The Law of Ueki), and Kaitō Kid and Shinichi Kudo (Detective Conan). His current starring roles include that of Yamada Hifumi (Danganronpa) and Raimon "Monta" Taro, the Deimon Devil Bats' wide receiver in Eyeshield 21. Yamaguchi is also best known as the Japanese voice of Kyle Broflovski, Bugs Bunny and Crash Bandicoot.
Yamaguchi has appeared in eroge as Kyōya Ushihisa (牛久 京也 Ushihisa Kyōya?).He made his first public appearance in North America at Otakon 2008; and was also a guest at Sakura-Con 2009. Yamaguchi's third appearance to date has been at Animazement in 2010. He also made a fourth appearance in Hawaii at Kawaii Kon in 2011.
He is married and has a son.
| Year | Image | Character | Title |
|---|---|---|---|
| 1999-Genzai | 
|
Usopp | One Piece: Wan pîsu |
| 1998-Genzai | 
|
Kyle Broflovski | South Park |
| 1998-Genzai | 
|
Clyde Donovan | South Park |
| 1995-Genzai | 
|
Mirukuchokorēto | M&M's: Emuandoemuzu |
| 2021 |  
|
Baggusu Banī | Space Players: Supēsu Pureiyāzu |
| 2015-2018 | 
|
Director Assitant | Dragon Ball Super: Doragon bôru Sūpā |
| 2011 | 
|
Blu | Rio |
| 2009-2011 | 
|
Burūtā | Popettsutaun |
| 2006 | 
|
Fūta | Gekijōban Dōbutsu no Mori |
| 2002-2005 | 
|
Bebī Baggusu | Bebī Rūnī Te~yūnzu |
| 2004 | 
|
Max Goof | Mickey's Twice Upon a Christmas |
| 2003 | 
|
Baggusu Banī | Baggusu Banī Shō |
| 1999 | 
|
Tooru | Pokemon Sunappu |
| 1997-1999 | 
|
Rattrap | Beast Wars: Transformers |
| 1996 | 
|
Julian | Fire Emblem: Faiā Emuburemu (Anime) |
| 1989-1992 | 
|
Ranma Saotome | Ranma ½ |
| 1979 |  
|
Baggusu Banī | Baggusu Banī no Kurisumasu |
| 1979 | 
|
Kuraido Banī | Baggusu Banī no Kurisumasu |