
Quick answer — Daichi Kanbara voices Cain in Promise of Wizard, Hokuto Ijuuin in The Idolm@ster: 765 Pro to Iu Monogatari, Yuusaku Suwa in All Out!! and 1 more characters.
Daichi Kanbara voices Cain (Promise of Wizard), Hokuto Ijuuin (The Idolm@ster: 765 Pro to Iu Monogatari), Yuusaku Suwa (All Out!!), Tullio Rossi (Reign of the Seven Spellblades).
Cain is voiced in Japanese by Daichi Kanbara.