
Quick answer — Aiko Hibi voices Zashiki Warashi in Mononoke, Kochu in Kaiba, Takeru Nekome in Den-noh Coil and 2 more characters.
Aiko Hibi voices Zashiki Warashi (Mononoke), Kochu (Kaiba), Takeru Nekome (Den-noh Coil), Kouhei (Saint☆Onii-san), Thomas Redmond (Steamboy).
Zashiki Warashi is voiced in Japanese by Aiko Hibi.