Tenth rank or grade. Tenth degree black belt in martial arts ranking systems. The only official 10th degree awarded through the AIKIKAI HOMBU was given to Koichi TOHEI c. 1970. Minoru MOCHIZUKI received this rank through the INTERNATIONAL MARTIAL ARTS FEDERATION. Michio HIKITSUCHI, Seiseki ABE and several others are reputed to have received this rank orally from Morihei UESHIBA, however, these are not officially registered at the Aikikai.