This is an example of a 1937-1942 pattern Imperial Japanese Navy flight suit. This was standard warm weather zone flight suit worn by naval aviators and aircrews.
This flying suit was obtained for research by the U.S. Army Air Forces Foreign Technology Division (FTD) during World War II. These items were made available for study by commercial firms who could then incorporate any improvements American flight clothing.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.