Premise: 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 Katagiri and was organized as follows:
Hypothesis: The Ministry of the Navy of Japan was responsible for more than the development and training of the Imperial Japanese Navy Air Service.