It is a sport of balletic beauty and extraordinary violence. Where else are you allowed to strangle an opponent unconscious? But while its aim is to inflict symbolic death, judo is a form of combat which also rigorously insists on the most formal courtesies. When Mark Law joined his local judo club he was able to observe at close quarters the sport practised at its highest level - finding himself face-to-face with world champions and Olympic medallists. His journey into judo took him to Osaka, J