Quick answer — Masato Sakai voices Sensei in Blue Literature Series, Shigemaru in Blue Literature Series, Yoshihide in Blue Literature Series and 3 more characters.
Masato Sakai voices Sensei (Blue Literature Series), Shigemaru (Blue Literature Series), Yoshihide (Blue Literature Series), Youzou Ooba (Blue Literature Series), Kray Foresight (Promare), Melos (Blue Literature Series).
Sensei is voiced in Japanese by Masato Sakai.
