The was a Japanese two-seat dive bomber/trainer designed and built by the Yokosuka Naval Air Technical Arsenal. Derived from the Aichi D3A, it was made nearly entirely of wood in an attempt to conserve valuable resources. Upon Japan's surrender, the project came to a halt with only a few aircraft delivered as the Navy Type 99 Bomber Trainer Myojo Model 22.
The D3Y was a two-seat bomber trainer constructed of wood, so as not to use more valuable materials. It was based on the successful Aichi D3A with design starting in late 1942. Like the D3A, it was a two-seat low-winged monoplane with a fixed tailwheel undercarriage. To allow construction by unskilled workers, the elliptical wing and rounded tail of the D3A were replaced by straight tapered alternatives, while the fuselage was lengthened to improve stability. Two prototypes were built during 1944, but these proved heavier than expected. Three production aircraft, which were redesigned to save weight, were completed for the Imperial Japanese Navy Air Service before the end of the war, and designated the Navy Type 99 Bomber Trainer Myojo Model 22.