List of dōjō in mainland Japan
OKIC has created a directory of Okinawa karate and kobudō dōjō outside of Okinawa prefecture. The purpose is to inform about the dōjō in mainland Japan that are affiliated with Okinawan organizations.
Currently, there are 236 Okinawa karate dojos registered in 39 prefectures out of 46 prefectures. The total number of dōjō is 236. Please check this PDF for the number of dōjō by prefecture.