Kanō Jigorō, Japanese martial artist (died 1938)

Kanō Jigorō was a Japanese judoka, educator, politician, and the founder of judo. Judo was one of the first Japanese martial arts to gain widespread international recognition, and the first to become an official Olympic sport. Pedagogical innovations attributed to Kanō include the use of black and white belts, and the introduction of dan ranking to show the relative ranking among members of a martial-art-style. Well-known mottoes attributed to Kanō include "maximum efficiency minimal effort" and "mutual welfare and benefit" .