Kouji Sawai was born September 14, 1955 in Tokyo, Japan.
During school Sawai always aimed to be mangaka. After graduating from Toyo University he joined Tatsunoko Production where he became a storyboarder and later episode director. After serving two more years as part of the production staff he left and became freelance episode director.
Today he works mainly for Bee Train, whose representative director Koichi Mashimo is a good friend of his.
Also storyboarded an episode of the American cartoon, "Real Ghost Busters" (Season 2, Episode 43; Ghost fight at the O.K. Corral)