
Quick answer — Kouichi Toochika voices Ryuu Amakusa in Detective School Q, Hawkmon in Digimon: Digital Monsters 02, Toyohiro Kanedaichi in JoJo's Bizarre Adventure: Diamond is Unbreakable and 13 more characters.
Kouichi Toochika voices Ryuu Amakusa (Detective School Q), Hawkmon (Digimon: Digital Monsters 02), Toyohiro Kanedaichi (JoJo's Bizarre Adventure: Diamond is Unbreakable), Neji Hyuuga (Naruto), Yuu Himura (ef ~ A Tale of Memories), Chic Craate (Infinite Ryvius), Kreis Morate (Infinite Ryvius), Genai (Chrono Crusade) and 8 more.
Ryuu Amakusa is voiced in Japanese by Kouichi Toochika.