The Shurikenjutsu reference article from the English Wikipedia on 24-Apr-2004
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Shurikenjutsu

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Shurikenjutsu is the Japanese art of throwing shuriken (ninja stars), knives and dirks. Shurikenjutsu is a koryu form.

This is not a very popular sport as its use is severly limited. Since the point is to throw so it will stub the opponent, you are to never likely to have a chance to test it on a real opponent. While this could have made this art a mere parlor trick, masters of this art have taken care to keep their knowledge intact by writing books to pass their knowledge.