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).
Known For: Directing
Birthday: 1966-03-29
Place of Birth: Urawa, Saitama, Japan
Also Known As: Sôichi Masui, Sōichi Masui, 増井 壮一, Soichi Masui, Kazuma Mizusaka, 水草一馬, ますい そういち, Kazuma Mizukusa