Kobayashi was born in Tama on September 18, 1981. She played for Nippon TV Beleza from 1997 to 2014. In her 18 seasons, she played 223 matches in Nadeshiko League. The club won Nadeshiko League championship 8 times and 2nd position 10 times. She also became top scorer in 2000 season and she was selected Best Eleven in 2000 and 2001.