Soejima was born in Saga on July 26, 1959. After graduating from high school, he joined Yanmar Diesel in 1978. After reserve team in 2 season, he was promoted top team in 1980. In 1980, the club won the champions in Japan Soccer League and he was selected Best Eleven. The club also won 1983 and 1984 Emperor's Cup. In 1991, he moved to Division 2 club Sumitomo Metal and played in 1 season. He retired in 1992.
After retirement, Soejima started coaching career at Kashima Antlers (former Sumitomo Metal) in 1992. He moved to Gamba Osaka in 1996. In 1998, he returned to Cerezo Osaka (former Yanmar Diesel) and became a manager in 2000. He was sacked in August 2001. He managed his local club Sagan Tosu in 2002 and Vissel Kobe in 2003. In 2005, he returned to Cerezo Osaka and managed youth team until 2008. He moved to Kataller Toyama and became a coach. In 2010, he moved to Thespa Kusatsu and managed until 2012. In 2015, he moved to Thailand and became a manager Ayutthaya.