Koji Seki

Acting • 1982-11-25 • Saitama, Japan

Koji Seki (関幸司, Seki Kōji, born November 25, 1982) is a Japanese voice actor from Saitama Prefecture who is affiliated with Raccoon Dog. He graduated from Pro-Fit Voice Actor Training School and joined the agency Pro-Fit. On April 1, 2022, he transferred to Raccoon Dog.

Known For

8.6

Haikyu!!

2014

8.2

I Got a Cheat Skill in Another World and Became Unrivaled in the Real World, Too

2023

8.3

Yashahime: Princess Half-Demon

2020

6.6

Let This Grieving Soul Retire

2024

6.9

Summer Pockets

2025

7.7

Sword Art Online the Movie – Progressive – Scherzo of Deep Night

2022

Fan Club

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Filmography

2026
You and I Are Polar OppositesTV
Convenience Store Manager (voice) • 2 episodes
★ 8.6
2026
Star Wars: Visions Presents - The Ninth JediTV
Satellite Digger (voice) • 2 episodes
★ 7.5
2026
Star Wars: Visions Presents - The Ninth JediTV
Eesha's Father (voice) • 1 episodes
★ 7.5
2026
Star Wars: Visions Presents - The Ninth JediTV
Villager on Samaz (voice) • 1 episodes
★ 7.5
2026
Akane-banashiTV
Chusuke Chuotei (voice) • 1 episodes
★ 7.7
2025
Welcome to the Outcast's Restaurant!TV
Merchant (voice) • 1 episodes
★ 7.5
2025
Solo Camping for TwoTV
Izakaya Manager (voice) • 1 episodes
★ 7.5
2025
Catch Me at the Ballpark!TV
Kaiser (voice) • 1 episodes
★ 7.8
2025
Summer PocketsTV
(voice) • 3 episodes
★ 6.9
2025
Inexpressive Kashiwada and Expressive OotaTV
Mathematics Teacher (voice) • 1 episodes
★ 7.2
2025
Turkey! Time to StrikeTV
Samurai (voice) • 1 episodes
★ 6.3
2024
Dan Da DanTV
TV Station Producer (voice) • 1 episodes
★ 8.5
2024
Dan Da DanTV
Male Client (voice) • 1 episodes
★ 8.5
2024
Dan Da DanTV
Male Teacher (voice) • 1 episodes
★ 8.5
2024
Mission: Yozakura FamilyTV
Detective (voice) • 1 episodes
★ 7.5
2024
Mission: Yozakura FamilyTV
(voice) • 1 episodes
★ 7.5
2024
Mission: Yozakura FamilyTV
Battalion member (voice) • 1 episodes
★ 7.5
2024
HAIKYU!! The Dumpster BattleFilm
Patient (voice)
★ 7.9
2024
Orb: On the Movements of the EarthTV
Knight (voice) • 1 episodes
★ 8.1
2024
Let This Grieving Soul RetireTV
Greg Zangief (voice) • 24 episodes
★ 6.6
2024
Puniru Is a Kawaii SlimeTV
Academic Researchers (voice) • 2 episodes
★ 7.7
2024
Puniru Is a Kawaii SlimeTV
Academic Researcher (voice) • 1 episodes
★ 7.7
2024
Umamusume: Pretty Derby - Beginning of a New EraFilm
(voice)
★ 8.6
2024
DAN DA DAN: First EncounterFilm
TV Station Producer (voice)
★ 7.5
2023
The Apothecary DiariesTV
Audience (voice) • 1 episodes
★ 8.7
2023
Frieren: Beyond Journey's EndTV
Villager (voice) • 1 episodes
★ 8.8
2023
NieR:Automata Ver1.1aTV
Kingdom Citizen (voice) • 1 episodes
★ 8.1
2023
NieR:Automata Ver1.1aTV
Machine Creature (voice) • 1 episodes
★ 8.1
2023
I Got a Cheat Skill in Another World and Became Unrivaled in the Real World, TooTV
(voice) • 7 episodes
★ 8.2
2023
The Aristocrat's Otherworldly Adventure: Serving Gods Who Go Too FarTV
Sebas (voice) • 1 episodes
★ 7.1
2023
Tearmoon EmpireTV
Priest (voice) • 2 episodes
★ 7.1
2023
Tearmoon EmpireTV
Man (voice) • 1 episodes
★ 7.1
2023
Tearmoon EmpireTV
Soldier (voice) • 1 episodes
★ 7.1
2023
Tearmoon EmpireTV
Merchant (voice) • 1 episodes
★ 7.1
2022
SPY x FAMILYTV
Rahden (voice) • 1 episodes
★ 8.5
2022
BLUE LOCKTV
Reporter B (voice) • 1 episodes
★ 8.3
2022
Sword Art Online the Movie – Progressive – Scherzo of Deep NightFilm
Naijan (voice)
★ 7.7
2021
Star Wars: VisionsTV
Eno's Father / Resistance Member (voice) • 1 episodes
★ 7.1
2021
I've Been Killing Slimes for 300 Years and Maxed Out My LevelTV
Store Customer E (voice) • 1 episodes
★ 7.8
2021
Remake Our Life!TV
(voice) • 1 episodes
★ 7.3
2021
Super CubTV
Clerk (voice) • 2 episodes
★ 7.3
2020
JUJUTSU KAISENTV
Fumi's Father (voice) • 1 episodes
★ 8.6
2020
Tower of GodTV
(voice) • 1 episodes
★ 8.1
2020
Yashahime: Princess Half-DemonTV
Thug (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Official (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Peddler (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Guard (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Old man (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Chimimoryo (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Villager (voice) • 4 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Peasant (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Bird of Paradise (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Subordinate (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Townsfolk (voice) • 2 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Vassal (voice) • 3 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Fisherman (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Demon (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Rock Demon (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Palanquin Carrier (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Green ogre (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Staff member (voice) • 1 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Yokai (voice) • 2 episodes
★ 8.3
2020
Yashahime: Princess Half-DemonTV
Raccoon dog in Mamiana Island (voice) • 1 episodes
★ 8.3
2020
ID: INVADEDTV
Staff (voice) • 1 episodes
★ 7.2
2019
The Quintessential QuintupletsTV
Teacher (voice) • 1 episodes
★ 8.4
2019
The Quintessential QuintupletsTV
Homeroom Teacher (voice) • 2 episodes
★ 8.4
2016
March Comes In Like a LionTV
Authorized Person 3 (voice) • 1 episodes
★ 8.0
2014
Haikyu!!TV
Kai Akakura (voice) • 4 episodes
★ 8.6
2012
Sword Art OnlineTV
Technical Staff (voice) • 1 episodes
★ 8.1
2012
Sword Art OnlineTV
Goblin (voice) • 1 episodes
★ 8.1
2012
Daily Lives of High School BoysTV
Basketball Guy (voice) • 1 episodes
★ 8.0
2012
Daily Lives of High School BoysTV
Boy B (voice) • 1 episodes
★ 8.0