What does this demonstration have to do with the martial arts?
Just little things, like better performance of technique, precision, timing, breathing.
To belittle good clean performance as being just a show is incorrect. The older traditions in the arts, Chinese and Okinawan, almost always had public perforance in their ways.
It pushes students to be better for another thing. It also has a very important way of teaching a student mistakes can hurt you, so don't make them.
bushi no te isshinryu
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