Oshima was born in Ōita Prefecture[1] on October 16, 1950. He attended Nakatsu Kogyo High School.[2] He was drafted by the Chunichi Dragons in the third round of the 1968 draft.[1]
Professional career
Playing
Oshima made his NPB debut with the Dragons in 1971.[2] He won two Central League pennants with the team.[1] His best year came in 1979, when he recorded a career-high batting average of .317,[2] and had the most hits in the league with 159.[1] He also hit 36 home runs that year, the most in his career, but finished behind Masayuki Kakefu (who hit 48) as the league leader in home runs.[3] Four seasons later, Oshima led the league in home runs with 36.[1][3] He joined the Nippon Ham Fighters in 1988, finishing his NPB career with the team in 1994. He played 2,638 games over his 24-year career, amassing 2,204 hits, 382 home runs, and 1,234 runs batted in.[1]
Coaching
Oshima became manager of the Fighters in 2000. He recorded his only winning season that same year, with the team finishing 69–65. Overall, he had a 181–225 record in his three seasons with the team.[2] He later became the hitting coach of the Japan national baseball team for the 2006 World Baseball Classic, the first edition of the tournament which the Japanese team won.[1]
Later life
Oshima was inducted into the Meikyukai. He disclosed in February 2017 that he had colon cancer.[4] He nonetheless continued working as a baseball commentator and also blogged about his fight against the disease. Oshima died on June 30, 2021, at the age of 70.[1]