Hiroshi Kobayashi first played soccer in the Japan Soccer League for the Furukawa Electric soccer club. (Currently, JEF United Ichihara Chiba.) He began his soccer coaching career in 1990 as coach of ALO's Hokuriku, which he coached through 1998 leading the team to promotion in the league. He then coached for the second half of 2001 for Division 1 club Kawasaki Frontale and the first 20 games of the 2002 season for Mito Hollyhock before becoming Mito's general manager. He was the president of Mito Hollyhock from 2002 to 2007.