
Quick answer — Katsuhiko Sasaki voices Mun-Deok Son in Yona of the Dawn, Masahiro Takenaka in Black Lagoon.
Katsuhiko Sasaki voices Mun-Deok Son (Yona of the Dawn), Masahiro Takenaka (Black Lagoon).
Mun-Deok Son is voiced in Japanese by Katsuhiko Sasaki.