Emperor Hirohito’s radio broadcast announcing Japan’s acceptance of surrender terms was called Gyokuon-hōsō.
The broadcast was transmitted on 15 August 1945 and is formally known as the Imperial Rescript on the Termination of the War. Hirohito recorded the speech the previous day, and it was broadcast at noon Japan Standard Time. It told listeners that Japan had accepted the terms of the Potsdam Declaration.
Many Japanese people had never heard the emperor’s voice before. The speech used formal classical Japanese, so some listeners did not immediately understand that it meant surrender. It referred to the use of a new and cruel bomb and to the changing international situation, without plainly using the everyday word “surrender.”
Gyokuon-hōsō literally refers to a broadcast of the emperor’s voice. It is not the name of the legal surrender document, which was signed later aboard USS Missouri on 2 September.