I did karate when I was younger, got to around yellow belt then I quit, I just don't like karate anymore, I would prefer to be doing Jeet kun do and/or Kendo

you can do the same in ninjutsu, and any other martial...the difference is Karate, and several others, require you to form a very dense callus on the palm and side of your hand. THAT's what a hardhand is

Moi has a purple belt from the isshinryu style of Karate although that was ages an ages ago. I gotta say that it was cool while it lasted! :)