Souichi Masui
- Birth Date
- 3/29/1966
- Birth Place
- Urawa, Saitama, Japan
- Known For
- Directing
Souichi Masui (増井 壮一, Masui Sōichi, born 1966) is a Japanese anime director and storyboard artist from Urawa City, Saitama Prefecture (currently Saitama City). He sometimes works under the pseudonym Kazuma Mizukusa (水草一馬).
