For anyone who’s interested, Hatsumi-sensei’s school is called Bujinkan Taijutsu and is practised in Japan, the US, New Zealand and other places. It’s a serious self-defense style and students train without mats, because if you need it to defend yourself, you’ll probably be on concrete. It comprises kicks, punches, throws, joint locks, weapons and poking opponents in the most painful nerves.
You’d be surprised how hard it is to hit anything with a throwing star.