
Quick answer — Hisayoshi Suganuma voices Jan Suk in Monster, Atsushi Kitamoto in Natsume's Book of Friends Season 1, Shirou Kikuchihara in World Trigger 2nd Season and 13 more characters.
Hisayoshi Suganuma voices Jan Suk (Monster), Atsushi Kitamoto (Natsume's Book of Friends Season 1), Shirou Kikuchihara (World Trigger 2nd Season), Fred Aberline (Black Butler: Book of Circus), Wonderweiss Margela (Bleach), Azami (Xam'd: Lost Memories), Connor Kluff (Letter Bee), Moc Sullivan (Letter Bee) and 8 more.
Jan Suk is voiced in Japanese by Hisayoshi Suganuma.