Sugai was born in Tokyo, to a Japanese father and a Russian mother.
He turned professional in 1975 and has won three tournaments and over 275 million ¥ on the Japan Golf Tour.
In 2002, he became the first Japanese to win the Senior British Open in what was the last staging before the tournament became a Champions Tour major.
He played on the European Seniors Tour in 2003 and 2004 with little success.
PGA of Japan Tour playoff record (1–1) Note: Sugai only played in The Open Championship.