Mitsuo Yamaguchi (山口 光雄, Yamaguchi Mitsuo), 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), Yattaro (Kyattou Ninden Teyandee), InuYasha (InuYasha), Ryuichi Sakuma (Gravitation), L (Death Note), Usopp (One Piece), Hideyoshi (Law of Ueki), and Kaito Kid and Shinichi Kudo (Case Closed). His current starring roles include that of Raimon "Monta" Taro, the Deimon Devil Bats' ace receiver in Eyeshield 21.
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 is married and has a daughter, Akane Yamaguchi (山口 茜), and a son, Ryunosuke Yamaguchi (山口 竜之介), who also are voice actors.
Description above from the Wikipedia article Kappei Yamaguchi, licensed under CC-BY-SA, full list of contributors on Wikipedia.
Movies
Detective Conan: Captured in Her Eyes Shinichi Kudo (voice)
Detective Conan: The Time Bombed Skyscraper Shinichi Kudo (voice)
Case Closed: The Fourteenth Target Shinichi Kudo (voice)
A Tree of Palme Roualt (voice)
One Piece: Clockwork Island Adventure Usopp (voice)
One Piece: The Desert Princess and the Pirates: Adventure in Alabasta Usopp (voice)
TIGER & BUNNY: The Beginning Robin Baxter (voice)
Inuyasha the Movie 3: Swords of an Honorable Ruler Inuyasha (voice)
Inuyasha the Movie 4: Fire on the Mystic Island Inuyasha (voice)
Ranma ½: Nightmare! Incense of Spring Sleep
Detective Conan: The Raven Chaser Shinichi Kudo (voice)
Detective Conan: The Last Wizard of the Century Shinichi Kudo / Kaito Kuroba (voice)
One Piece Film: Strong World Usopp (voice)
One Piece: The Great Treasure of Tongari Island Usopp (voice)
One Piece - En route vers l'épisode 1000 Comédien de doublage de Usopp – Japon
A Wind Named Amnesia Johnny (voice)
Detective Conan: The Story of Ai Haibara: Black Iron Mystery Train Kaito Kuroba (voice)
One Piece Special: Protect! The Last Great Stage Usopp (voice)
Dead Leaves Retro (voice)
La Blue Girl: Climax Taizan Nin-Nin
Plastic Little: The Adventures of Captain Tita Nicole
Kiki's Delivery Service Tombo (voice)
One Piece Episode of East Blue Usopp (voice)
Neighborhood Story The Movie Tsutomu Yamaguchi (voice)
Escaflowne: The Movie Shesta (voice)
Space Battleship Yamato Resurrection Ryohei Nakanishi
Rurouni Kenshin: Requiem for the Ishin Patriots Yasuharu Musashino
One Piece: Episode of Chopper Plus: Bloom in the Winter, Miracle Cherry Blossom Usopp (voice)
Grappler Baki: The Ultimate Fighter Baki Hanma
One Piece: Giant Mecha Soldier of Karakuri Castle Usopp (voice)
One Piece: The Movie Usopp (voice)
One Piece Special: The Detective Memoirs of Chief Straw Hat Luffy Usopp (voice)
Ressha Sentai ToQger Final Live Tour 2015 Ticket / ToQger Equipment Voice (voice)
Welcome to Lodoss Island! Etoh (voice)
Noiseman Sound Insect Manabu (voice)
Eternal Family Sasuke (voice)
Heisei Rider vs. Showa Rider: Kamen Rider Wars feat. Super Sentai ToQger Equipment Voice
Ressha Sentai ToQger DVD Special: Farewell, Ticket! The Wasteland Super ToQ Battle! Ticket (voice)
Gosho Aoyama’s Collection of Short Stories
Violence Jack: Hell's Wind Saburo Tenma
One Piece 3D: Straw Hat Chase Usopp (voice)
Silent Mobius Gaiden: The End of the Edo Period
One Piece "3D2Y": Overcome Ace's Death! Luffy's Vow to his Friends Usopp (voice)
Heart and Yummie Heart (voice)
Detective Conan: The Eleventh Striker Shinichi Kudo (voice)
Detective Conan: Jolly Roger in the Deep Azure Shin'ichi Kudo (voice)
Detective Conan: Full Score of Fear Shinichi Kudo (voice)
Shadow Skill: The Movie Scrib Lowengren
Detective Conan OVA 10: Kid in Trap Island Kaito Kid / Kaito Kuroba
One Piece: Episode of Luffy - Hand Island Adventure Usopp (voice)
Appleland Story Virgil
One Piece Film: Z Usopp (voice)
One Piece: Episode of Alabasta - Prologue Usopp (voice)
One Piece 3D: Gekisou! Trap Coaster Usopp (voice)
One Piece: Glorious Island Usopp (voice)
One Piece Film Gold: Episode 0 Usopp (voice)
Pokémon Mystery Dungeon: Explorers of Time & Darkness Chimchar (voice)
Giant Robo: The Day the Earth Stood Still Daisaku Kusama
Ressha Sentai ToQger vs. Kyoryuger: The Movie Ticket (voice)
Detective Conan: Private Eye in the Distant Sea Shinichi Kudo (voice)
The Adventures of Tyrano Boy Zesta (voice)
The Adventures of Tyrano Boy Bard (voice)
One Piece Episode of Merry: The Tale of One More Friend Usopp
Shuriken Sentai Ninninger vs. ToQger the Movie: Ninjas in Wonderland Ticket (voice), ToQger Equipment Voice
Hunter x Hunter: Phantom Rouge Feitan (voice)
Ressha Sentai ToQger vs. Kamen Rider Gaim: Spring Break Combined Special Ticket / ToQger Equipment (voice)
Detective Conan: Black Iron Submarine Shinichi Kudou (voice)
Case Closed: The Million-Dollar Pentagram Kaito Kid / Shinichi Kudou (voice)
One Piece Film Red Usopp (voice)
Detective Conan: Dimensional Sniper Shinichi Kudo (voice)
Lupin the Third vs. Detective Conan: The Movie Shinichi Kudo / Kaito Kuroba (voice)
Asura
Okaeri: Furusato no Karatsu Sora Hiroi (voice)
Detective Conan: Sunflowers of Inferno Shinichi Kudo / Kaitou Kid (voice)
Ressha Sentai ToQger The Movie: Galaxy Line S.O.S. Ticket / ToQger Equipment / Narrator (voice)
One Piece: The Desert Princess and the Pirates: Adventure in Alabasta Lashes (voice)
Detective Conan Magic File 2: Shinichi Kudo, The Case of the Mysterious Wall and the Black Lab 主演
One Piece Special: Open Upon the Great Sea! A Father's Huge, HUGE Dream! Usopp (voice)
Ryokunohara Labyrinth - Sparkling Phantom Kanata Tokino
Detective Conan vs. Kid the Phantom Thief Kaito Kuroba / Kaito Kid (voice)
Virgin Fleet Sada
Detective Conan: The Bride of Halloween Shinichi Kudo (voice)
Tottoi Billia (voice)
Detective Conan: The Scarlet School Trip Shinichi Kudo (voice)
Lupin the Third vs. Detective Conan Shinichi Kudo (voice)
Detective Conan: The Private Eyes' Requiem Shinichi Kudo (voice) / Kaito Kuroba (voice)
Detective Conan: Quarter of Silence Shinichi Kudo (voice)
Luffy's Fall! The Unexplored Region - Grand Adventure in the Ocean's Navel Usopp (voice)
Ressha Sentai ToQger Returns: Super ToQ #7 of Dreams Ticket (voice)
The Boy and the Beast Teenage Jiromaru (voice)
Kamiwaza Wanda
Engimon
One Piece: Adventure of Nebulandia Usopp (voice)
Detective Conan: The Darkest Nightmare Shinichi Kudo (voice)
1+2=Paradise Yūsuke Yamamoto (voice)
PERSONA4 the Animation -The Factor of Hope- Kuma
GinRei Special OVA Daisaku Kusama
K.O. Beast
Magical Circle Guru Guru
Madara (voice)
Battle Angel Yūgo (voice)
Inuyasha the Movie: Affections Touching Across Time Inuyasha (voice)
One Piece Film: GOLD Usopp (voice)
Yu-Gi-Oh!: Bonds Beyond Time Daitokuji (voice)
Urotsukidōji II: Legend of the Demon Womb Young Munchausen II (voice)
Detective Conan OVA 01: Conan VS KID VS Yaiba
Case Closed: The Crimson Love Letter Shinichi Kudo (voice)
Kishin Douji Zenki Gaiden: Anki Kitan Zenki
Death Note Relight 1: Visions of a God L (voice)
Desperate Love Katsumi Shibuya (voice)
One Piece Episode of Sabo: The Three Brothers' Bond - The Miraculous Reunion and the Inherited Will Usopp
One Piece: Jango's Dance Carnival Usopp (voice)
One Piece: Dream Soccer King! Usopp
Case Closed: Countdown to Heaven Shinichi Kudo (voice)
Detective Conan: The Phantom of Baker Street Shinichi Kudo (voice)
Death Note Relight 2: L's Successors L (voice)
Detective Conan: Crossroad in the Ancient Capital Shinichi Kudo (voice)
Bonobono: Secret of the Kumomo Tree Araiguma-kun
One Piece: Chopper's Kingdom on the Island of Strange Animals Usopp (voice)
Please Save My Earth Hirohiko Kazama (voice)
Futari wa Precure Splash☆Star the Movie: Tic-Tac Crisis Hanging by a Thin Thread! Flappy (voice)
Kindaichi Case Files Movie 1: The Opera House Murders Hajime Kindaichi (Voice)
One Piece: Baron Omatsuri and the Secret Island Usopp (voice)
One Piece: Dead End Adventure Usopp (voice)
Chibi Maruko-chan: My Favorite Song Kenichi Oono (voice)
Pretty Guardian Sailor Moon Special Act: We're Getting Married!！
Pretty Guardian Sailor Moon: Act Zero
Boyfriend Ougi (voice)
Barefoot Gin Rei Daisaku Kusama (voice)
One Piece: Episode of Skypiea Usopp (voice)
One Piece: Heart of Gold Usopp (voice)
Case Closed: The Fist of Blue Sapphire Shinichi Kudo / Kaito Kuroba (voice)
One Piece: Romance Dawn Story Usopp (voice)
The Disappearance of Conan Edogawa: The Worst Two Days in History Shinichi Kudo (voice)
One Piece Episode of Nami: Tears of a Navigator and the Bonds of Friends Usopp (voice)
Detective Conan: Strategy Above the Depths Shinichi Kudou (voice)
Case Closed: Zero the Enforcer Shinichi Kudo / Kaito Kid (voice)
Urusei Yatsura: The Obstacle Course Swim Meet, It's a Rumic World: Urusei Yatsura (voice)
Peacemaker Kurogane: Belief Shinpachi Nagakura (voice)
Devil Hunter Yohko
Mazinger Z: Infinity Mucha (voice)
Chibi Maruko-chan Kenichi Oono (voice)
Shadow Skill: Epilogue Scrib Lowengren (voice)
Nineteen 19 Hiroaki Kusano (voice)
Yona Yona Penguin Mulmul (voice)
Detective Conan: Magician of the Silver Sky Kaito Kid / Shinichi Kudou (voice)
One Piece: Stampede Usopp (voice)
Atashin'chi: The 3D Movie Fujino (voice)
One Piece: Curse of the Sacred Sword Usopp (voice)
Detective Conan: Episode One - The Great Detective Turned Small Shinichi Kudo (voice)
Zyuden Sentai Kyoryuger vs. Go-Busters: The Great Dinosaur War ToQger equipment (voice)
It's a Rumic World: 50th Anniversary Weekly★Shonen Sunday Inuyasha / Ranma Saotome ♂ (voice)
Camp Pikachu Barubeat (voice)
Pokémon: Pikachu's Rescue Adventure Parasect (voice)
Detective Conan: The Lost Ship in the Sky Shinichi Kudo / Kaito Kid (voice)
Animal Crossing: The Movie Fûta (voice)
Tomcat's Big Adventure Michael (voice)
Ranma ½: The Movie — The Battle of Nekonron: The Fight to Break the Rules! Ranma Saotome ♂ (voice)
Ranma ½: The Movie 2 — The Battle of Togenkyo: Rescue the Brides! Ranma Saotome ♂ (voice)
Ranma ½: The Movie 3 — The Super Non-Discriminatory Showdown: Team Ranma vs. the Legendary Phoenix Ranma Saotome ♂ (voice)
The Mighty Gin Rei Daisaku Kusama (voice)
Inuyasha the Movie 2: The Castle Beyond the Looking Glass Inuyasha (voice)
Detective Conan: The Scarlet Bullet Shinichi Kudo (voice)
Tomorrow I'll be Lively ~Half Sweet Potato~
Nagasaki 1945 ~ The Angelus Bells
Inferious Interplanetary War Chronicle - Condition Green Oscar Cloud (voice)
Delinquent in Drag Suke Banji
Crows
Dragon Knight: Wheel of Time Kakeru
Pichu & Pikachu's Winter Vacation 2001 Delibird (voice)
Bronze: Zetsuai Since 1989 Shibuya (voice)
Pretty Cure All Stars DX: Everyone Is a Friend - A Miracle All Pretty Cures Together Flappy
Pretty Cure All Stars DX2: The Light of Hope - Protect the Rainbow Jewel! Flappy (voice)
Pretty Cure All Stars DX3: Deliver the Future! The Rainbow-Colored Flower That Connects the World Flappy
Pretty Cure All Stars New Stage: Friends of the Future Flappy
Baby Felix & Friends Poindexter
Hanappe Bazooka Hanappe Yamada (voice)
Futari wa Precure Splash☆Star: Maji Doki Theater Flappy (voice)
Mouse Story: The Adventures of George and Gerald Chamberlain
Coicent White Deer (voice)
Dream 9 Toriko & One Piece & Dragon Ball Z Super Collaboration Special!! Usopp (voice)
Detective Conan Bonus File 1: Flower of Fantasista
Ultraman Super Fighter Legend Astra / Announcer Banjou (voice)
One Piece: Ice Hunter Ussop (voice)
Shows
ODDTAXI Eiji Kakihana (voice)
Yat, The Space Patrol カナビー
Jewel BEM Hunter Lime バース (voice)
Jujutsu Kaisen Kechizu (voice)
The Cockpit Soldier Utsunomiya (voice)
The Ancient Magus' Bride: The Boy from the West and the Knight of the Blue Storm Oberon (voice)
Ressha Sentai ToQger Ticket (voice)
La Blue Girl Nin-Nin (voice)
Dragon Knight: Wheel of Time Kakeru (voice)
Pretty Guardian Sailor Moon Artemis (voice)
Bondage Queen Kate Dick (voice)
The Law of Ueki Hideyoshi Soya (voice)
Flint: The Time Detective Kyoichiro Narugami
Fancy Lala Taro Yoshida
My Family Fujino (voice)
Pecola Bashatt
Powerpuff Girls Z
The Legend of Lyon: Flare Eon
Yu-Gi-Oh! GX Professor Daitokuji / Lyman Banner (voice)
Samurai Pizza Cats Yattarou
Galaxy Warring State Chronicle Rai (voice)
Neighborhood Story Tsutomu Yamaguchi (Voice)
CLAMP School Detectives (voice)
Cyber Team in Akihabara Crane Bahnsteik (voice)
Android Kikaider Saburo Kazeda (voice)
Valkyria Chronicles
Stitch! Kijimuna
Nadia: The Secret of Blue Water Hamahama (voice)
Gun Frontier
Can Can Bunny Extra Kenta (voice)
Baby and Me
Step Up Love Story
One Outs Satoshi Ideguchi (voice)
B'T X Camilla (voice)
Case Closed Jimmy Kudo
Gravitation Ryuichi Sakuma (voice)
Betterman Keita Aono (voice)
Ayakashi: Samurai Horror Tales Kaikaimaru (voice)
Neo Angelique Abyss Rune
Hanada Shounen-shi Haruhiko (voice)
DearS (voice)
Eyeshield 21 Raimon Tarou
Kiba Hugh (voice)
InuYasha InuYasha (voice)
Shippuu! Iron Leaguer Kiwami Juurouta
Majikoi - Oh! Samurai Girls Ikuro Fukumoto (voice)
PreCure Splash Star Flappy (voice)
Our Home's Fox Deity
Wedding Peach Takuro Amano
Papuwa Chappy
Papuwa Dr. Gunma
Ranma ½ Ranma Saotome
Red Baron Ken Kurenai
Red Baron Fake Ken
Baccano! Chic Jefferson (voice)
Miracle Girls Yuuya Noda
One Piece Usopp (voice)
Sister Princess
Lil' Red Riding Hood Cha-Cha
Eden's Bowy Jorrne
Zenki Zenki (voice)
Rizelmine Tomonori Iwaki
Angelic Layer
Kamikaze Kaitou Jeanne Noin Claude
Doki Doki School Hours Kenta Suetake
Cowboy Bebop Rhint (voice)
Armored Dragon Legend Villgust Bostov (voice)
Persona4 the ANIMATION Teddie (voice)
Lady Blue Nin-Nin (voice)
Yashahime: Princess Half-Demon Inuyasha (voice)
Tokusou Sentai Dekaranger Thousanian Gineka (voice)
Tensou Sentai Goseiger Ain-I of the Neutral (voice)
Doubutsu Sentai Zyuohger Illusion (voice)
Reinou Tantei Miko: Phantom Hunter Miko Rokuro Kanda (voice)
KO Century Beast Warriors Wan Dababatta
Jungle King Taa-chan Etekichi
Death Note L (voice)
Tokyo Babylon Subaru Sumeragi (voice)
RG Veda Ryū-ō (voice)
Mobile Fighter G Gundam Sai Saici (voice)
Magi: Adventure of Sinbad Valefor (voice)
Rin-ne Sabato Rokudou
Ghastly Prince Enma Burning Up
The Little Judge from Hell Enma (voice)
Devil Hunter Yohko Wakabayashi Osamu (voice)
Revolutionary Girl Utena Shiori's boyfriend (voice)
Giant Robo: The Day the Earth Stood Still Daisaku Kusama
Here Is Greenwood Tenma Koizumi (voice)
Ayane's High Kick Kappei Inagaki (voice)
Space Academy Jii-chan (voice)
Battle Angel Yugo (voice)
Hunter x Hunter Feitan (voice)
Sore Ike! Zukkoke Sannin-gumi Hachibee
Hakkenden: Legend of the Dog Warriors Sosuke Inukawa (voice)
GinRei
Genji Tsuushin Agedama Hikari Yumenokōji (voice)
Persona 4 The Golden Animation Teddie (voice)
Space Pirate Captain Herlock: Outside Legend - The Endless Odyssey Tochiro (voice)
Makeruna!! Aku no Gundan! Pepu (voice)
The Twelve Kingdoms Rokuta (voice)
Record of Lodoss War Etoh (voice)
BUCCHIGIRI?! Komao (voice)
Mighty Space Miners Ushiwaka Nanbu (voice)
Super Dragon Ball Heroes Fu (voice)
GeGeGe no Kitaro Ittan Momen
Madara Madara (voice)
Captain Tsubasa J Ryou Ishizaki (voice)
JoJo's Bizarre Adventure Shigechi (voice)
RADIANT Master Lord Majesty (voice)
Case Closed Shinichi Kudo (voice)
Sgt. Frog Tororo
Magic Kaito 1412 Kaito Kuroba / Shinichi Kudo (voice)
One Piece Characters Log Usopp
Zetsuai-1989 Katsumi Shibuya (voice)
Peacemaker Shinpachi Nagakura (voice)
Shadow Skill Low (voice)
Gigant Big-Shot Tsukasa Tsukasa Mendō (voice)
1+2=Paradise Yūsuke Yamamoto
Urusei Yatsura Saizo (voice)
Super Zugan
Magic Kaito: Kid the Phantom Thief Kaito Kuroba / Kaito Kid (voice)
Urusei Yatsura Tsuyuo (voice)
Pop Team Epic Popuko (voice)
Urusei Yatsura B-Bo (voice)
Rampo Kitan: Game of Laplace Shitai-kun
Angel's Feather Hamura Shou (voice)
In Search of the Lost Future Osafune Kenny Eitarou
BOFURI: I Don't Want to Get Hurt, so I'll Max Out My Defense. Shin (voice)
Showa Genroku Rakugo Shinju Amaken (voice)
Hikonin Sentai Akibaranger Chief Clerk Blu-Ray (voice)
Hikonin Sentai Akibaranger Chief Editor HVD (voice)
Danganronpa: The Animation Hifumi Yamada (voice)
Claymore Male 'Awakened' 3 (voice)
Free Kick Toward Tomorrow Toto
Legend of the Dragon Kings Amaru Ryudou
Vinland Saga Jabbathe (voice)
The Ancient Magus' Bride Oberon (voice)
Ranma1/2 Ranma Saotome (voice)
The Heroic Legend of Arslan: Age of Heroes Arslan (voice)
Slow Step Akiba Shuu
Fire Emblem Julian (voice)
Monkey Typhoon Goku (voice)
The Gymnastics Samurai Bigbird Aragaki (voice)
Viper GTS Ogawa (voice)
Please Save My Earth Hirohiko Kazama (voice)
Mecha-Ude: Mechanical Arms Yakumo (voice)
Ranma ½ Ranma Saotome ♂ (voice)
Mouse Sorata Muon (voice)
Bakuage Sentai Boonboomger Ticket (voice)
One Piece Log: Fish-Man Island Saga Usopp
