The Imperial Japanese Navy Aviation Bureau (海軍航空本部, Kaigun Kōkū Hombu) of the Ministry of the Navy of Japan was responsible for the development and training of the Imperial Japanese Navy Air Service.
In 1941 it was headed by Vice-Admiral Eikichi Katagiri and was organized as follows: Training for the IJNAS are conducted under training unit led directly by the Naval Air Bureau.
Such unit could either be an actual combat air group(Kōkūtai) or a proper training unit.
Such schools and units was named after the place where they were established (cities, towns or Arsenal/Base), or with the carrier name if it is a carrier based unit.
For example, the 12th combined air group(training) based at Kure consist of the Ōita, Usa, Hakata and Ōmura training air group.