A3 Champions Cup (aka East Asian Champions Cup) is an annual friendly football event involving the league champions of China, Japan and South Korea. The host nation also invites an additional domestic club, making this a 4 team tournament.
The one-off Far East Club Championship 1998 can be considered a fore-runner of this tournament. Begun in 2003, the A3 Champions Cup serves as the de-facto regional club tournament for East Asia as the EAFF currently only holds national team tournaments. The major problem is that the A3 Champions Cup only has the big 3 nations and excludes the other smaller nations. It has been suggested that the league champion from Australia may be added to the cup in the future.