Koike was born in Shizuoka Prefecture on August 24, 1980.
After graduating from Shizuoka Gakuen High School, he joined the newly promoted J2 League club, Oita Trinita in 1999.
On May 22, he debuted as a substitute midfielder in the 82nd minute against Sagan Tosu.
[1][2] However he only played in that match and retired at the end of the 2000 season.
This biographical article related to a Japanese association football midfielder born in the 1980s is a stub.