The popular answer is Gichin Funakoshi. Wrong. The true answer is Anko Itosu. He is the man responsible for bringing karate to the public in Okinawa via the school system which led to it's public introduction in Japan. Karate is not Japanese but rather it is Okinawan. It blew up in Japan and spread like wildfire so that is where the large misconception of karate being Japanese stems from.