The Yokosuka D4Y Suisei (彗星, "comet") was a dive bomber of the Imperial Japanese Navy. Its Allied codename was "Judy". The D4Y was one of the fastest dive-bombers in the entire war, and only the delays in its development hindered its service, while its predecessor, the more robust but slower Aichi D3A remained in service for years. Despite this limited use, the speed and the range of the D4Y was nevertheless valuable, and the type was used with success as reconnaissance aircraft as well as in kamikaze missions.