
Quick answer — Keita Hayakawa voices Ooba Gundan Tanaka in ON-GAKU: OUR SOUND, Ooba Gundan Yamamoto in ON-GAKU: OUR SOUND.
Keita Hayakawa voices Ooba Gundan Tanaka (ON-GAKU: OUR SOUND), Ooba Gundan Yamamoto (ON-GAKU: OUR SOUND).
Ooba Gundan Tanaka is voiced in Japanese by Keita Hayakawa.