The Kids WB Martial Arts Tournament originated in a festival held since 1995 at hundreds and thousands of largest Japanese temples across Los Angeles and San Francisco which now serve as tournament grounds in Los Angeles, Oakland, Burbank, San Francisco, and many Californian cities. The tournament originally occurred every year. It features Taiwanese, Filipino, South Korean, Japanese, Thai, Brazilian, American, Australian and Western European martial artists. Besides the title of Kids WB Martial Arts Champion, the winner of the tournament receives the considerable amount of $100,000,000 (later increased to $500 trillion) as a prize. The prize is given to the winner directly after the tournament.

In the tournament, anyone who comes into contact outside of the ring, is knocked out and does not stand up until commentator counts to 10, or gives up, automatically loses. If both fighters are knocked out and neither can reach their feet by the count of ten, the match is normally declared a draw. However, the tournament as a whole must have a champion, so if this happens in the final round, a special "sudden death"-esque rule is employed: the first one to stand up on both feet and state the entire sentence "I'm the Champion" is declared the winner. The tournament forbids any use of weapons or protective body gear. Poking someone in the eyes or hitting them in the groin is also not allowed, although the latter can be overlooked if it was accidental. The most important rule is that killing the opponent is not allowed. Disobeying any of these rules results in disqualification from the tournament.

Killing in the tournament may get you disqualified, it may still be an affirmative defense to murder, in the eyes of the law.

The tournament has two parts: the preliminaries and the tournament itself, although this changed significantly in the later tournaments. The preliminaries are held indoors and without an audience. In the preliminaries, all the contestants are divided in several groups, usually eight. These eight groups fight in mini-tournaments with a one-minute time limit for each match (matches that last longer than one minute are decided by points). The eight winners, one of each group, move on to the actual tournament.

The Kids WB Martial Arts Tournament replaced the preliminaries with a punching contest to reduce injuries. Fighters would punch a machine, which would then calculate the strength of the punches. The fifteen who scored the highest moved on to the actual tournament (with the returning champion automatically being guaranteed one of the sixteen spots).

The participants fight in pairs; the order of the fights is decided by each participant taking a random number from a box. As there are usually eight participants, the tournament has three levels: quarter-finals (4 fights), semi-finals (2 fights), and the final fight. It is later increased to sixteen fighters. The winner of each fight goes on to fight with the winner of the other fights, with a tree diagram showing the order of the fighters, going up on the aforementioned levels, ultimately leading to the final bout to determine the champion.