Shirai was born in Fuji on June 17, 1974. After graduating from Tokai University Daiichi High School, he joined his local club Shimizu S-Pulse in 1993. However his opportunity to play increased, he could hardly play in the match in 1996. He moved to Verdy Kawasaki (1997) and Cerezo Osaka (1998). After a year's blank, he joined J2 League club Shonan Bellmare in 2000. He played for Bellmare in 6 seasons. He moved to Vegalta Sendai in 2006. Initially he played as regular player. However he lost regular position for injury in June 2006. He moved to Japan Football League club FC Ryukyu in 2008. However he could hardly play in the match for injury. He retired end of 2008 season.