Biografía: Koji Seki (関 幸司, Seki Kōji, nacido el 25 de noviembre de 1982) es un actor de voz (seiyū) japonés de la prefectura de Saitama afiliado a Raccoon Dog. Se graduó de la Escuela de Formación de Actores de Voz de Pro-Fit y se unió a dicha agencia. El 1 de abril de 2022 se transfirió a Raccoon Dog.
Conocido por:

7.7
Sword Art Online Progressive Movie II - Kuraki Yuuyami no Scherzo

7.7
Dan Da Dan: First Encounter

7.9
3-gatsu no Lion

7.6
Super Cub

8.2
Sword Art Online

8.2
Sword Art Online

7.9
Slime Taoshite 300-nen, Shiranai Uchi ni Level Max ni Nattemashita

8.1
NieR:Automata Ver1.1a

8.2
Isekai de Cheat Skill wo Te ni Shita Ore wa, Genjitsu Sekai wo mo Musou Suru - Level Up wa Jinsei wo Kaeta

8.5
The Quintessential Quintuplets

8.5
The Quintessential Quintuplets

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

7.3
Bokutachi no Remake

8.3
Yashahime: Princess Half-Demon

7.3
Tensei Kizoku no Isekai Boukenroku; Jichou wo Shiranai Kamigami no Shito

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
BLUELOCK

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.3
Yashahime: Princess Half-Demon

8.6
Jujutsu Kaisen

8.6
Haikyuu!! Los ases del vóley

8.1
NieR:Automata Ver1.1a

8
Danshi Koukousei no Nichijou

8
Danshi Koukousei no Nichijou

8.7
DAN DA DAN

8.7
DAN DA DAN

8.3
Tower of God

8.7
DAN DA DAN

8.6
Puniru is a Kawaii Slime

7.4
Mission: Yozakura Family

7.4
Mission: Yozakura Family

7.4
Mission: Yozakura Family

7.5
Let This Grieving Soul Retire

7.9
Tierra, sangre, conocimiento: Sobre el movimiento de la Tierra