The kōdōkan was founded in 1882 by Kanō Jigorō, the founder of judo, and is now an eight-story building in Tokyo.

The growth of judo in its early years is demonstrated by the growth of the Kodokan itself:[9] Today, the Kodokan has 1,206 mats across the five main dojo (training halls)—Main, School, International, Women's, and Boys'—plus a special dojo for retired judoka and special technique study purposes.

[14][15][16][17][18] In 1994 Keiko Fukuda became the first woman to be awarded a rare red belt (at the time for women still marking the 8th dan rank) in judo by the Kodokan.

[17] In 2006 the Kodokan awarded Keiko Fukuda the 9th degree black belt (9th dan), making her the first woman to hold this rank from any recognized judo organization.

[19] There are eight floors and a basement to the Kodokan dojo, each serving purposes for housing, training, and research by judoka.

The extensive library on the second floor holds over 7,000 books pertaining to judo, and is planned to be increased eventually.

The dojo is carefully designed to give the precise amount of floor spring, brightness, and ventilation.

Only white judogi (judo uniforms) are generally allowed in the Kodokan (except for special occasions and foreign guests for whom they may show some tolerance).