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Kōichi Yamadera

Kōichi Yamadera

Voice Actor

Kōichi Yamadera is a Japanese voice actor, narrator and singer affiliated with Across Entertainment, who voiced Ryoji Kaji in the original Neon Genesis Evangelion.

Agency: Across Entertainment
Role: Voice Actor
Nationality: Japanese
Years Active: 1985-present
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Neon Genesis Evangelion Role

In the original Neon Genesis Evangelion, Yamadera voices Ryoji Kaji, the enigmatic NERV agent and Misato's on-and-off lover who quietly investigates the Instrumentality Project before his fate catches up with him. The role sits among Yamadera's earliest major anime credits and showcases the wry, laid-back delivery that became his signature.

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Career and Notable Roles

One of Japan's most prolific voice actors, Yamadera is also known for Spike Spiegel in Cowboy Bebop, Togusa in Ghost in the Shell, Beerus in Dragon Ball Super, and Jūbei Kibagami in Ninja Scroll, alongside long-running work as the official Japanese dub voice of Will Smith, Eddie Murphy, and Disney's Donald Duck.

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Frequently Asked Questions

Who does Koichi Yamadera voice?

Yamadera is internationally recognized for voicing Spike Spiegel in Cowboy Bebop and Togusa in Ghost in the Shell, two of the most acclaimed anime series of the 1990s. He built this reputation as one of Japan's most prolific voice actors across decades of anime work.

What is Koichi Yamadera's most famous role?

Yamadera's most famous role is widely considered to be Spike Spiegel in Cowboy Bebop. He is also well known outside anime as the official Japanese dub voice of Hollywood stars Will Smith and Eddie Murphy, as well as Disney's Donald Duck.

Who voices Beerus in Japanese?

Koichi Yamadera voices Beerus, the god of destruction, in Dragon Ball Super. He also played Jubei Kibagami in Ninja Scroll, another major action role that showcases his range beyond comedic parts.

Who does Koichi Yamadera voice in Neon Genesis Evangelion?

In the original Neon Genesis Evangelion, Yamadera voices Ryoji Kaji, the enigmatic NERV agent who quietly investigates the Instrumentality Project while carrying on an on-and-off relationship with Misato Katsuragi. It was one of his earliest major anime credits and showcased the wry, laid-back delivery that became his signature.

Who is Koichi Yamadera?

Koichi Yamadera is a Japanese voice actor, narrator and singer born in 1961 and affiliated with the agency Across Entertainment. He has been active in the industry since 1985, building one of the most prolific careers in Japanese voice acting.

Sources & Information

This content is original writing by Daddy Jim Headquarters based on the Dragon Ball anime series, manga, and official materials. Episode and chapter references are cited where applicable.

Character and scene imagery on this site is original artwork by Daddy Jim Headquarters, not screenshots or licensed imagery. Official cover art is used on three types of pages for editorial commentary:

  • Movie pages: theatrical posters and key visuals, credited to Toei Animation and Shueisha.
  • Game pages: official box art, credited to Bandai Namco, Atari, and other publishers.
  • Manga chapter pages: Jump Comics volume covers, credited to Shueisha and Akira Toriyama.

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