Bio: Born in Gifu Prefecture, Kōyama attended Nihon University but quit midway to join the independent production company Kindai Eiga Kyokai, where he worked as an assistant director under such directors as Kaneto Shindō, Kōzaburō Yoshimura, and Tadashi Imai. He made his directorial debut in 1971 with thechildren's film Koi no iru mura
