The method of teaching the martial art of Aikido developed by Kenji Tomiki adopted many of the teaching principles developed by Jigaro Kano, the founder of Judo, including the introduction of competition and an emphasis more on free-form randori sparring when compared to other styles of Aikido.
Toshu randori, which is performed barehanded, involves both participants performing moves on the other while simultaneously resisting and countering the other's moves.
In tanto randori, one participant is designated as the attacker (tantō) and the other is empty-handed and is designated as the defender (toshu). The attacker will use a training knife and perform moves to stab the defender. The defender will use any of seventeen basic aikido moves to throw the attacker. The attacker also attempts to counter the defender's moves by using only five designated aikido moves. In competitions, both participants switch roles and spend the equal time being the attacker and the defender.
Points between 1/2 and 4 are awarded for various moves and 1/2 point penalties for fouls. The participant with the most points (minus penalties) at the end of the fight is the winner.
The Aikido World Championships is a major international martial art competition for the sport which is conducted every two years. The event location alternates between Japan and cities in different countries.