
Quick answer — Akihiko Ishizumi voices Jack Chu in Kaiba, Georges Pontmercy in Les Misérables: Shoujo Cosette, Carlo in Cautious Hero: The Hero Is Overpowered but Overly Cautious and 3 more characters.
Akihiko Ishizumi voices Jack Chu (Kaiba), Georges Pontmercy (Les Misérables: Shoujo Cosette), Carlo (Cautious Hero: The Hero Is Overpowered but Overly Cautious), Amaryouju (Zakuro), Urushihara no Otto (Antique Bakery), Terumasa Nanjou (Umineko: When They Cry).
Jack Chu is voiced in Japanese by Akihiko Ishizumi.