Omiya Ardija
Kawashima started his professional career at Omiya Ardija in J2 League after graduating Urawa Higashi High School. On 6 April 2002, he made his Omiya Ardija debut. He went on to make 41 appearances for the side during his three-year spell. During his time at Omiya Ardija, Kawashima went on trial at Serie A side Parma.