Rank in Judo are ranked in ascending numerical order. The ninth ("kudan") and tenth degree black belt ("jūdan") and, theoretically, those higher, have no formal requirements. Only 15 individuals have been promoted to the rank of Kōdōkan 10th dan. On January 6, 2006, three individuals were promoted to this rank simultaneously: Daigo Toshirō, Ichirō Abe, and Ōsawa Yoshimi. This is the most ever at the same time, and the first in 22 years. No one has ever been promoted to a rank higher than 10th "dan", but in theory the Judo rank system is not limited to 10 degrees of black belt. The
Dan (rank) Dan (rank) The ranking system is used by many Japanese organizations and Korean martial arts to indicate the level of one's ability within a certain subject matter. As a ranking system, it was originally used at a go school during the Edo period. It is now also used in modern fine arts and martial arts. The system was applied to martial arts in Japan by Kanō Jigorō (1860–1938), the founder of judo, in 1883, and later introduced to other East Asian countries. In the modern Japanese martial arts, holders of dan ranks often wear a black belt; those of higher