
Quick answer — Ryouhei Arai voices Willem Kmetsch in WorldEnd: What are you doing at the end of the world? Are you busy? Will you save us?, Tasuku Kuresawa in Sasaki and Miyano, Taniguchi in TONIKAWA: Over The Moon For You Season 2 and 2 more characters.
Ryouhei Arai voices Willem Kmetsch (WorldEnd: What are you doing at the end of the world? Are you busy? Will you save us?), Tasuku Kuresawa (Sasaki and Miyano), Taniguchi (TONIKAWA: Over The Moon For You Season 2), Keisuke Shinjou (Days with My Stepsister), Seto (One Piece: Episode of Skypiea).
Willem Kmetsch is voiced in Japanese by Ryouhei Arai.