Formula Toyota
Kageyama began his career by winning the inaugural 1990 Formula Toyota championship. In 1991 he moved up to the All-Japan Formula Three Championship and finished fourth with one win. He embarked on a full-fledged touring car racing campaign in 1992, competing in the All Japan Touring Car Championship Class 3 in a Honda Civic, finishing 9th. He also continued in Japanese F3 but failed to finish in the points.