Kousuke Oonishi (大西 弘祐, Ōnishi Kōsuke, born May 7, 1991) is a Japanese voice actor (seiyū) from Saitama prefecture who is associated with Arts Vision. He graduated from the Nihon Narration Engi Kenkyūjo (Japan Narration Acting School). His hobbies and special skills are puns and singing.

Credits