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
Judo dan rank in the 1880s, initially the wide obi was used; as practitioners trained in kimono, only white and black obi were used. It was not until the early 1900s, after the introduction of the judogi, that an expanded colored belt system of awarding rank was created. Judo The philosophy and subsequent pedagogy developed for judo became the model for other modern Japanese martial arts that developed from . The early history of judo is inseparable from its founder, Japanese polymath and educator , born . Kano was born into a relatively affluent family. His father, Jirosaku, was the second