
Quick answer — Ryou Katsuji voices Shinjuurou Yuuki in UN-GO, Agito in Origin: Spirits of the Past, Koutarou Yuda in The Case of Hana & Alice and 1 more characters.
Ryou Katsuji voices Shinjuurou Yuuki (UN-GO), Agito (Origin: Spirits of the Past), Koutarou Yuda (The Case of Hana & Alice), Descartes Shaman (Mobile Suit Gundam 00 the Movie: A Wakening of the Trailblazer).
Shinjuurou Yuuki is voiced in Japanese by Ryou Katsuji.