One time, we were holding a demonstration in the town's park.
It was a weekend where we had a booth in the park, since it was "merchant's exhibition weekend." We conducted the demonstration just as we would a regular class, with a couple of weapons kata also shown. Nothing fancy, just good, fundamentally strong, Karate.
There was a rival school in the area, that also claimed to teach traditional martial arts. They wanted to one-up us, so their instructor put on a sword kata, where he was actually jumping and spinning while slashing around with that sword. Now I don't know about most of you, but when I see someone doing a 360 degree jump and spin during a weapons kata, I find it rather... humorous.
Then the instructor had his assistant hit him with a shinai (bamboo sword) several times in the gut, so he could show how tough he was, giving loud kiai each time he was struck. He then told the assistant to hit him on the triceps, but she missed, instead cracking him across the forehead.
Those were some interesting words coming from his mouth after that, once he recovered from the hit (he had his hands covering his face for about 10 seconds).
We were invited to come back next year. They weren't.
