
Quick answer — Hiroshi Koujina worked on Hunter x Hunter (2011) (Director), Hajime no Ippo: The Fighting! (Chief Animation Director), Rainbow (Director) and 6 more anime.
Hiroshi Koujina worked on Hunter x Hunter (2011) (Director), Hajime no Ippo: The Fighting! (Chief Animation Director), Rainbow (Director), The Vampire Dies in No Time Season 2 (Director), Neuro: Supernatural Detective (Director), The Vampire Dies in No Time (Director), KIBA (Director), Amon: The Apocalypse of Devilman (Character Design) and 1 more.