
Quick answer — Youhei Hamada voices Keibiin in Mitsuboshi Colors, Tenzen Kanou in Summer Pockets, Hiroshi Ookado in Tsugumomo and 5 more characters.
Youhei Hamada voices Keibiin (Mitsuboshi Colors), Tenzen Kanou (Summer Pockets), Hiroshi Ookado (Tsugumomo), Line P (Girlish Number), Ik-Han U (Noblesse), Gil (Management of a Novice Alchemist), Takashi (Ninja Vs. Gokudo), Klaus Tospan (Saga of Tanya the Evil Season 2).
Keibiin is voiced in Japanese by Youhei Hamada.