The competition started on March 8, and finished on November 3, 2003.
Teams from the J1 took part in the tournament.
Kashima Antlers and Shimizu S-Pulse were given a bye to the quarter-final due to their qualification for the AFC Champions League.
The rest of 14 teams started from the group stage, where they're divided into four groups.
The group winners of each group qualifies for the quarter-final along with the runners-up of group A and B, and the two teams which qualified for the AFC Champions League.