Kodokan was founded by Tokugawa Nariaki in 1841 for Samurai and their children of Mito Domain. The admission age as 15 and there was no graduation or completion age.

Both traditional academics and military art were emphasized at the school, which also had one of the nation's best premises. Smiliar to modern university, the Kodokan had academic halls like Seicho and Nobility hall where students learned traditional subjects, an artistic wing for learning military arts, as well as medicine, astronomical observatory, racecourses for horseback riding, and an area for military training.

The section where the Eight trigrams hall, Kashima shrine, and Confucian temple were built was considered sacred grounds. At the academic halls, students learned like Confucianism, history, astronomy, mathematics, and music. Subjects like sword fighting, spearing, military strategy, and equestrian skills were taught in the artistic wing of the school.

Seicho Room
A large literary examination room.

Seicho Common Room
Room for visitors and those who were excused from various military duties.

Nobility Hall
The feudal lord's recreation room.
Tokugawa Yoshinobu, the last Shogun, was confined in this room after the Meiji Restoration.

There are many Tokugawa related items, including their drawing and painting arts in the building.