Judo is one of the most popular sports played in Japan.
Judo literally means "gentle way". Judo takes from ju-jitsu ("gentle art") the principle of using one's opponent's strength against him.
Kano saw ju-jitsu as a disconnected bag of tricks, and sought to unify it according to some principle: he found it in the notion "maximum efficiency". With that, he renamed his art "judo", to indicate his view of it as a means of physical and spiritual development,as well as self-defense.
Judo has become Olympic Sport and is now internationally very popular.
The belt color represent the level of the player. White is the biginner and the black is skilled.