Kappei Yamaguchi (山口勝平), real name Mitsuo Yamaguchi (山口光雄), born May 23, 1965, in Fukuoka, Japan, is a voice actor who played Artemis in Pretty Guardian Sailor Moon. His other roles include male Ranma Saotome in Ranma ½, InuYasha in InuYasha, Yattaro in Cats Toninden Teyande (the Japanese version of Speedy Cerviche from Samurai Pizza Cats), Rokuta (Enki) in Twelve Kingdoms, Usopp/SogeKing in One Piece, Floppy in Futari wa Pretty Cure Splash Star, Takurou Amano in Ai Tenshi Densetsu Wedding Peach and Wedding Peach DX, Daitokuji in Yu-Gi-Oh!! Duel Monsters GX, Danny in Konjiki no Gash Bell!!, and L in Death Note.
- He is also an illustrator for anime and voice actor magazines/books.