
Quick answer — Shouzou Hayashiya IX voices Koutarou Matsudaira in Touch, Ponkichi in Pom Poko, Rokai in Ninja Scroll: The Series.
Shouzou Hayashiya IX voices Koutarou Matsudaira (Touch), Ponkichi (Pom Poko), Rokai (Ninja Scroll: The Series).
Koutarou Matsudaira is voiced in Japanese by Shouzou Hayashiya IX.