The hierarchical structure of Aikido follows substantially the ranking system adopted by almost all other major martial arts. The students of the art are divided into two categories: one including students of kyu rank, and the other including students of dan rank.
The category of kyu rank embraces students of Aikido who have not yet attained the rank of dan and have not yet received their black belt. Collectively they are known as mundansha, or undergraduates.
The category of dan rank embraces those students of Aikido who have been awarded their black belts. Collectively they are known as yudansha (black belt holders).
CATEGORIES AND RANKS OF THE AIKIDO HIERARCHY
The Kyu Category & Its Ranks
rank of 6th kyu | (rokyu) | Green Belt
rank of 5th kyu | (gokyu) | Green Belt
rank of 4th kyu | (yonkyu) | Blue Belt
rank of 3rd kyu | (sankyu) | Blue Belt
rank of 2nd kyu | (nikyu) | brown belt | Hakama
rank of 1st kyu | (ikkyu) | brown belt
The Dan Category and Its Ranks
rank of 1st dan | (shodan) | Black Belt
rank of 2nd dan | (nidan) | Fuku-Shidoin (assistant instructor)
rank of 3rd dan | (sandan) | Fuku-Shidoin (assistant instructor)
rank of 4th dan | (yodan) | Shidoin (instructor)
rank of 5th dan | (godan) | Shidoin (instructor)
rank of 6th dan | (rokudan) | Shidoin (instructor)
rank of 7th dan | (shichidan) | Shihan (master instructor)
rank of 8th dan | (hachidan) | higher