Genos, the powerful cyborg disciple of Saitama in One-Punch Man, is voiced in Japanese by Kaito Ishikawa. In the English dub, Genos is voiced by Zach Aguilar in later productions and by Chris Niosi in Season 1. Ishikawa’s intense and emotionally restrained performance became a defining part of Genos’ character, balancing unwavering determination, loyalty, and explosive combat energy. (Behind The Voice Actors)

Japanese Voice Actor: Kaito Ishikawa

Date of Birth

October 13, 1993 (Wikipedia)

About Kaito

Kaito Ishikawa is a Japanese voice actor known for portraying disciplined, intelligent, and emotionally driven protagonists across anime and gaming. His role as Genos in One-Punch Man became one of his breakthrough performances thanks to Genos’ serious personality, emotional backstory, and visually intense battle scenes.

Ishikawa’s calm but forceful vocal style helped establish Genos as one of modern anime’s most recognizable cyborg characters. His performance also complements Makoto Furukawa’s deadpan Saitama, creating one of the franchise’s signature comedic dynamics.

Outside of One-Punch Man, Ishikawa is widely recognized for voicing Tobio Kageyama in Haikyuu!!, Naofumi Iwatani in The Rising of the Shield Hero, Tenya Iida in My Hero Academia, and Sakuta Azusagawa in Rascal Does Not Dream of Bunny Girl Senpai. (Wikipedia)

Hometown

Tokyo, Japan (Wikipedia)

Career Highlights

Genos — One-Punch Man
Tobio Kageyama — Haikyuu!!
Naofumi Iwatani — The Rising of the Shield Hero
Tenya Iida — My Hero Academia
Sakuta Azusagawa — Rascal Does Not Dream of Bunny Girl Senpai
Dante Zogratis — Black Clover
Reinhard van Astrea — Re:Zero
Lancelot — The Seven Deadly Sins: Four Knights of the Apocalypse
Rook Hunt — Disney Twisted-Wonderland (Wikipedia)

Full Current Filmography

The following list reflects documented major credits from publicly available and officially released productions.

Anime

One-Punch Man — Genos
Haikyuu!! — Tobio Kageyama
The Rising of the Shield Hero — Naofumi Iwatani
My Hero Academia — Tenya Iida
Rascal Does Not Dream of Bunny Girl Senpai — Sakuta Azusagawa
Black Clover — Dante Zogratis
Re:Zero − Starting Life in Another World — Wilhelm van Astrea (young)
Blue Lock — Rin Itoshi
Mashle: Magic and Muscles — Lance Crown
Your Lie in April — Ryōta Watari
A Sign of Affection — Itsuomi Nagi
Tokyo Ravens — Harutora Tsuchimikado
Occultic;Nine — Yūta Gamon
Sword Art Online Alternative: Gun Gale Online — M
The Seven Deadly Sins — Arthur Pendragon (Behind The Voice Actors)

Anime Films

One-Punch Man OVAs and specials — Genos
Rascal Does Not Dream film series — Sakuta Azusagawa
Haikyuu!! The Dumpster Battle — Tobio Kageyama
My Hero Academia: Heroes Rising — Tenya Iida
The Seven Deadly Sins: Prisoners of the Sky — Arthur Pendragon (IMDb)

Video Games

One Punch Man: A Hero Nobody Knows — Genos
Genshin Impact — supporting Japanese dub roles
Disney Twisted-Wonderland — Rook Hunt
Honkai: Star Rail — additional Japanese voices
Fire Emblem Heroes — multiple characters
Granblue Fantasy — various roles
Persona 3 Reload — additional voices
Blue Protocol — featured roles (Behind The Voice Actors)

Critical Reception

Kaito Ishikawa’s portrayal of Genos is widely praised for balancing stoic determination with emotional vulnerability. Fans frequently highlight his dramatic battle cries and emotionally charged scenes involving Genos’ search for vengeance against the Mad Cyborg.

His chemistry with Makoto Furukawa’s Saitama is also considered one of the central strengths of One-Punch Man, especially during comedic mentor-disciple interactions.

Our Sources

Behind The Voice Actors – Genos (https://www.behindthevoiceactors.com/characters/One-Punch-Man/Genos/)

Wikipedia – Kaito Ishikawa (https://en.wikipedia.org/wiki/Kaito_Ishikawa)

IMDb – Kaito Ishikawa (https://www.imdb.com/name/nm4826978/)

Behind The Voice Actors – Kaito Ishikawa (https://www.behindthevoiceactors.com/voice-actors/Kaito-Ishikawa/)

Wikipedia – Genos (https://en.wikipedia.org/wiki/Genos_(One-Punch_Man))

Social Media

X / Twitter: https://x.com/ish_kaito

Official Agency Profile: https://www.stardust.co.jp/talent/section3/ishikawakaito/

English Voice Actors: Chris Niosi and Zach Aguilar

About the English Dub Casting

Genos has had two credited English voice actors across major One-Punch Man releases:

Chris Niosi voiced Genos in the English dub of One-Punch Man Season 1.
Zach Aguilar took over the role beginning with Season 2 and has continued voicing Genos in later productions and games. (Behind The Voice Actors)

Because of the casting transition, both actors are associated with the character among English-speaking fans.

Chris Niosi

Date of Birth

Not publicly documented from official verified sources.

About Chris

Chris Niosi is an American voice actor, animator, and creator who voiced Genos in the English dub of One-Punch Man Season 1. His intense and emotionally serious performance matched Genos’ driven personality and dramatic battle sequences, helping establish the English version of the character during the anime’s breakout popularity.

Outside of One-Punch Man, Niosi has worked in anime dubbing, independent animation, and video game voice acting projects. (Behind The Voice Actors)

Hometown

New Jersey, USA (widely reported, though detailed official hometown documentation is limited).

Career Highlights

Genos — One-Punch Man Season 1
Reigen Arataka — early Mob Psycho 100 media projects
Therion — Octopath Traveler
Male Byleth — Fire Emblem Heroes (initial casting)
Various indie animation and gaming roles (IMDb)

Full Current Filmography

The following list reflects documented major credits from publicly available sources.

Anime

One-Punch Man Season 1 — Genos
Mob Psycho 100 — additional voices / related media
Pokémon — additional voices (Behind The Voice Actors)

Video Games

Octopath Traveler — Therion
Disgaea 5 — additional voices
Fire Emblem Heroes — Male Byleth (initial release)
AI: The Somnium Files — additional voices (IMDb)

Critical Reception

Chris Niosi’s portrayal of Genos in Season 1 is often remembered for its intensity and seriousness, especially during major combat scenes against enemies like Mosquito Girl and Deep Sea King. Many fans praised the chemistry between his Genos and Max Mittelman’s Saitama during the anime’s original run.

Our Sources

Behind The Voice Actors – Chris Niosi (https://www.behindthevoiceactors.com/voice-actors/Chris-Niosi/)

IMDb – Chris Niosi (https://www.imdb.com/name/nm3713228/)

Behind The Voice Actors – Genos (https://www.behindthevoiceactors.com/characters/One-Punch-Man/Genos/)

Zach Aguilar

Date of Birth

February 21, 1998 (Wikipedia)

About Zach

Zach Aguilar became the English voice of Genos beginning with One-Punch Man Season 2. His performance brought a slightly younger, more emotionally expressive tone to the character while preserving Genos’ intense loyalty and battle-focused mindset.

Aguilar quickly became one of the most recognizable younger anime dub actors of his generation. Outside of One-Punch Man, he is widely known for voicing Tanjiro Kamado in Demon Slayer, David Martinez in Cyberpunk: Edgerunners, Aether in Genshin Impact, and Koichi Hirose in JoJo’s Bizarre Adventure. (Wikipedia)

Hometown

Los Angeles, California, USA (IMDb)

Career Highlights

Genos — One-Punch Man Season 2 onward
Tanjiro Kamado — Demon Slayer
David Martinez — Cyberpunk: Edgerunners
Aether — Genshin Impact
Koichi Hirose — JoJo’s Bizarre Adventure: Diamond Is Unbreakable
Arthur Pendragon — Fire Force
Nasa Yuzaki — TONIKAWA
Milo — Pokémon Horizons (Wikipedia)

Full Current Filmography

Anime

One-Punch Man Season 2 — Genos
Demon Slayer — Tanjiro Kamado
Cyberpunk: Edgerunners — David Martinez
JoJo’s Bizarre Adventure — Koichi Hirose
Fire Force — Arthur Boyle
TONIKAWA — Nasa Yuzaki
Blue Exorcist — Renzo Shima
Tokyo Revengers — Takemichi Hanagaki
86 Eighty-Six — Dustin Jaeger
My Hero Academia — additional voices (Behind The Voice Actors)

Anime Films

Demon Slayer: Mugen Train — Tanjiro Kamado
One-Punch Man specials — Genos
Jujutsu Kaisen 0 — additional voices (IMDb)

Video Games

Genshin Impact — Aether
Persona 3 Reload — Ken Amada
Fire Emblem Engage — additional voices
Octopath Traveler II — Hikari
Granblue Fantasy: Relink — supporting voices
One Punch Man: A Hero Nobody Knows — Genos (Behind The Voice Actors)

Critical Reception

Zach Aguilar’s portrayal of Genos received praise for adding emotional warmth and vulnerability to the character while maintaining his intensity during action scenes. Fans particularly appreciated his chemistry with Max Mittelman’s Saitama and his performances during Genos’ more reflective moments in Season 2.