Portrait of Koji Seki

Koji Seki

Bio: 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
Born: Thu, Nov 25 1982
Birthplace: Saitama, Japan
Koji Seki is 42 years old
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Acting Roles
Crew Roles

Movies (Acting Roles)

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Poster of DAN DA DAN: First Encounter
DAN DA DAN: First Encounter
Koji Seki was 41 in DAN DA DAN: First Encounter as 'TV Station Producer (voice)'.
Movie Released: Sat, Aug 31 2024
Poster of Sword Art Online the Movie – Progressive – Scherzo of Deep Night
Sword Art Online the Movie – Progressive – Scherzo of Deep Night
Koji Seki was 39 in Sword Art Online the Movie – Progressive – Scherzo of Deep Night as 'Naijan (voice)'.
Movie Released: Sat, Oct 22 2022

TV Shows (Acting Roles)

Sorted by Release Date
Ages in TV shows are based off the first air date and may not be accurate. View individual episode details for accurate ages
Poster of Catch Me at the Ballpark!
Catch Me at the Ballpark!
Koji Seki was 42+ in Catch Me at the Ballpark! as 'Kaiser (voice)'.
TV Show Released: First Air Date
Wed, Apr 02 2025
Poster of Puniru Is a Kawaii Slime
Puniru Is a Kawaii Slime
Koji Seki was 41+ in Puniru Is a Kawaii Slime as 'Academic Researchers (voice)'.
TV Show Released: First Air Date
Sun, Oct 06 2024
Poster of Orb: On the Movements of the Earth
Orb: On the Movements of the Earth
Koji Seki was 41+ in Orb: On the Movements of the Earth as 'Knight (voice)'.
TV Show Released: First Air Date
Sat, Oct 05 2024
Poster of Dan Da Dan
Dan Da Dan
Koji Seki was 41+ in Dan Da Dan as 'TV Station Producer (voice), Male Client (voice), Male Teacher (voice)'.
TV Show Released: First Air Date
Fri, Oct 04 2024
Poster of Let This Grieving Soul Retire
Let This Grieving Soul Retire
Koji Seki was 41+ in Let This Grieving Soul Retire as 'Greg Zangief (voice)'.
TV Show Released: First Air Date
Tue, Oct 01 2024
Poster of Mission: Yozakura Family
Mission: Yozakura Family
Koji Seki was 41+ in Mission: Yozakura Family as 'Detective (voice), (voice), Battalion member (voice)'.
TV Show Released: First Air Date
Sun, Apr 07 2024
Poster of Tearmoon Empire
Tearmoon Empire
Koji Seki was 40+ in Tearmoon Empire as 'Priest (voice), Man (voice), Soldier (voice), Merchant (voice)'.
TV Show Released: First Air Date
Sun, Oct 08 2023
Poster of I Got a Cheat Skill in Another World and Became Unrivaled in the Real World, Too
I Got a Cheat Skill in Another World and Became Unrivaled in the Real World, Too
Koji Seki was 40+ in I Got a Cheat Skill in Another World and Became Unrivaled in the Real World, Too as '(voice)'.
TV Show Released: First Air Date
Fri, Apr 07 2023
Poster of The Aristocrat's Otherworldly Adventure: Serving Gods Who Go Too Far
The Aristocrat's Otherworldly Adventure: Serving Gods Who Go Too Far
Koji Seki was 40+ in The Aristocrat's Otherworldly Adventure: Serving Gods Who Go Too Far as 'Sebas (voice)'.
TV Show Released: First Air Date
Mon, Apr 03 2023
Poster of NieR:Automata Ver1.1a
NieR:Automata Ver1.1a
Koji Seki was 40+ in NieR:Automata Ver1.1a as 'Kingdom Citizen (voice), Machine Creature (voice)'.
TV Show Released: First Air Date
Sun, Jan 08 2023
Poster of BLUE LOCK
BLUE LOCK
Koji Seki was 39+ in BLUE LOCK as 'Reporter B (voice)'.
TV Show Released: First Air Date
Sun, Oct 09 2022
Poster of Remake Our Life!
Remake Our Life!
Koji Seki was 38+ in Remake Our Life! as '(voice)'.
TV Show Released: First Air Date
Sat, Jul 03 2021
Poster of I've Been Killing Slimes for 300 Years and Maxed Out My Level
I've Been Killing Slimes for 300 Years and Maxed Out My Level
Koji Seki was 38+ in I've Been Killing Slimes for 300 Years and Maxed Out My Level as 'Store Customer E (voice)'.
TV Show Released: First Air Date
Sat, Apr 10 2021
Poster of Super Cub
Super Cub
Koji Seki was 38+ in Super Cub as 'Clerk (voice)'.
TV Show Released: First Air Date
Wed, Apr 07 2021
Poster of Yashahime: Princess Half-Demon
Yashahime: Princess Half-Demon
Koji Seki was 37+ in Yashahime: Princess Half-Demon as 'Thug (voice), Old man (voice), Peddler (voice), Official (voice), Guard (voice), Villager (voice), Chimimoryo (voice), Bird of Paradise (voice), Peasant (voice), Townsfolk (voice), Subordinate (voice), Vassal (voice), Demon (voice), Fisherman (voice), Rock Demon (voice), Palanquin Carrier (voice), Green ogre (voice), Staff member (voice), Yokai (voice), Raccoon dog in Mamiana Island (voice)'.
TV Show Released: First Air Date
Sat, Oct 03 2020
Poster of JUJUTSU KAISEN
JUJUTSU KAISEN
Koji Seki was 37+ in JUJUTSU KAISEN as 'Fumi's Father (voice)'.
TV Show Released: First Air Date
Sat, Oct 03 2020
Poster of Tower of God
Tower of God
Koji Seki was 37+ in Tower of God as '(voice)'.
TV Show Released: First Air Date
Thu, Apr 02 2020
Poster of ID: INVADED
ID: INVADED
Koji Seki was 37+ in ID: INVADED as 'Staff (voice)'.
TV Show Released: First Air Date
Mon, Jan 06 2020
Poster of The Quintessential Quintuplets
The Quintessential Quintuplets
Koji Seki was 36+ in The Quintessential Quintuplets as 'Teacher (voice), Homeroom Teacher (voice)'.
TV Show Released: First Air Date
Fri, Jan 11 2019
Poster of March Comes In Like a Lion
March Comes In Like a Lion
Koji Seki was 33+ in March Comes In Like a Lion as 'Authorized Person 3 (voice)'.
TV Show Released: First Air Date
Sat, Oct 08 2016
Poster of Haikyu!!
Haikyu!!
Koji Seki was 31+ in Haikyu!! as 'Kai Akakura (voice)'.
TV Show Released: First Air Date
Sun, Apr 06 2014
Poster of Sword Art Online
Sword Art Online
Koji Seki was 29+ in Sword Art Online as 'Technical Staff (voice), Goblin (voice)'.
TV Show Released: First Air Date
Sun, Jul 08 2012
Poster of Daily Lives of High School Boys
Daily Lives of High School Boys
Koji Seki was 29+ in Daily Lives of High School Boys as 'Basketball Guy (voice), Boy B (voice)'.
TV Show Released: First Air Date
Tue, Jan 10 2012