This ranking system was introduced by Kanō Jigorō, the founder of judo, in 1883 and the first "dan" grades were awarded to his students Saigō Shirō and Tomita Tsunejirō.
This ranking system was introduced by Kanō Jigorō. The founder of judo and the first "dan" grades were awarded to his students Saigō Shirō and Tomita Tsunejirō Kanō Jigorō. This was in 1883.