[1] Okumura won the WPA World Nine-ball Championship in 1994, defeating Yasunari Itsuzaki in an all Japanese final.

Until Nick Varner won the world 9-Ball title in 1999, Okumura was the oldest champion.

Although he won the world nine-ball crown, Okumura wasn't quite successful in the sport for the next ten years.

In 1995, he almost won the International Challenge of Champions but Chao Fong-pang of Taiwan bested him in the last match.

He also was closing to winning the U.S. Open 9-ball Championship in 2000 but lost to Earl Strickland, 5-11, in the finals.