
Quick answer — Kazuo Oka voices Shouichi Matsunaga in March comes in like a lion, Chad in Planetes, Ryuunosuke Azumi in Tsukigakirei and 1 more characters.
Kazuo Oka voices Shouichi Matsunaga (March comes in like a lion), Chad (Planetes), Ryuunosuke Azumi (Tsukigakirei), Kenzou Sakiyama (Rumbling Hearts).
Shouichi Matsunaga is voiced in Japanese by Kazuo Oka.