Personal Info

Known For

Acting

Gender

Male

Birthday

11/25/1982

Place of Birth

Saitama, Japan

Also Known As

Kouji Seki関幸司Kōji Seki

Koji Seki

Biography

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

Umamusume: Pretty Derby - Beginning of a New Era

as (voice)

HAIKYU!! The Dumpster Battle

as Patient (voice)

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

as Naijan (voice)

DAN DA DAN: First Encounter

as TV Station Producer (voice)

Career Timeline

2025

Inexpressive Kashiwada and Expressive Oota

as Mathematics Teacher (voice)

Solo Camping for Two

as Izakaya Manager (voice)

Turkey! Time to Strike

as Samurai (voice)

Welcome to the Outcast's Restaurant!

as Merchant (voice)

Summer Pockets

as (voice)

Catch Me at the Ballpark!

as Kaiser (voice)

2024

Puniru Is a Kawaii Slime

as Academic Researchers (voice)

Puniru Is a Kawaii Slime

as Academic Researcher (voice)

Orb: On the Movements of the Earth

as Knight (voice)

Dan Da Dan

as TV Station Producer (voice)

Dan Da Dan

as Male Client (voice)

Dan Da Dan

as Male Teacher (voice)

Let This Grieving Soul Retire

as Greg Zangief (voice)

DAN DA DAN: First Encounter

as TV Station Producer (voice)

Movie

Umamusume: Pretty Derby - Beginning of a New Era

as (voice)

Movie

Mission: Yozakura Family

as Detective (voice)

Mission: Yozakura Family

as (voice)

Mission: Yozakura Family

as Battalion member (voice)

HAIKYU!! The Dumpster Battle

as Patient (voice)

Movie

2023

Tearmoon Empire

as Priest (voice)

Tearmoon Empire

as Man (voice)

Tearmoon Empire

as Soldier (voice)

Tearmoon Empire

as Merchant (voice)

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

as (voice)

The Aristocrat's Otherworldly Adventure: Serving Gods Who Go Too Far

as Sebas (voice)

NieR:Automata Ver1.1a

as Kingdom Citizen (voice)

NieR:Automata Ver1.1a

as Machine Creature (voice)

2022

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

as Naijan (voice)

Movie

BLUE LOCK

as Reporter B (voice)

SPY x FAMILY

as Rahden (voice)

2021

Star Wars: Visions

Role unknown

Remake Our Life!

as (voice)

I've Been Killing Slimes for 300 Years and Maxed Out My Level

as Store Customer E (voice)

Super Cub

as Clerk (voice)

2020

Yashahime: Princess Half-Demon

as Thug (voice)

Yashahime: Princess Half-Demon

as Official (voice)

Yashahime: Princess Half-Demon

as Peddler (voice)

Yashahime: Princess Half-Demon

as Guard (voice)

Yashahime: Princess Half-Demon

as Old man (voice)

Yashahime: Princess Half-Demon

as Chimimoryo (voice)

Yashahime: Princess Half-Demon

as Villager (voice)

Yashahime: Princess Half-Demon

as Peasant (voice)

Yashahime: Princess Half-Demon

as Bird of Paradise (voice)

Yashahime: Princess Half-Demon

as Subordinate (voice)

Yashahime: Princess Half-Demon

as Townsfolk (voice)

Yashahime: Princess Half-Demon

as Vassal (voice)

Yashahime: Princess Half-Demon

as Fisherman (voice)

Yashahime: Princess Half-Demon

as Demon (voice)

Yashahime: Princess Half-Demon

as Rock Demon (voice)

Yashahime: Princess Half-Demon

as Palanquin Carrier (voice)

Yashahime: Princess Half-Demon

as Green ogre (voice)

Yashahime: Princess Half-Demon

as Staff member (voice)

Yashahime: Princess Half-Demon

as Yokai (voice)

Yashahime: Princess Half-Demon

as Raccoon dog in Mamiana Island (voice)

JUJUTSU KAISEN

as Fumi's Father (voice)

Tower of God

as (voice)

ID: INVADED

as Staff (voice)

2019

The Quintessential Quintuplets

as Teacher (voice)

The Quintessential Quintuplets

as Homeroom Teacher (voice)

2016

March Comes In Like a Lion

as Authorized Person 3 (voice)

2014

Haikyu!!

as Kai Akakura (voice)

2012

Sword Art Online

as Technical Staff (voice)

Sword Art Online

as Goblin (voice)

Daily Lives of High School Boys

as Basketball Guy (voice)

Daily Lives of High School Boys

as Boy B (voice)