On what date did Emperor Hirohito’s recorded surrender message reach Japan by radio?

Emperor Hirohito’s recorded surrender message reached Japan by radio on August 15, 1945.

Broadcast at noon Japan Standard Time, the message announced that Japan had accepted the terms of the Potsdam Declaration. It was the first time many Japanese people had heard the emperor’s voice. The recording was made on August 14 and replayed the next day by Japan’s national broadcaster, NHK.

The speech used formal Classical Japanese and poor-quality audio, so many listeners found it difficult to understand. Hirohito did not use a simple phrase equivalent to “Japan surrenders.” Instead, he said that Japan had decided to accept the Allied declaration and end the war.

The announcement came after intense political debate inside Japan and a failed attempt by military officers to seize the recording and prevent its broadcast. The formal surrender ceremony followed on September 2 aboard USS Missouri. Thus, August 15 marks the public announcement, while September 2 marks the signed surrender.