NHK transmitted Hirohito’s surrender speech on 15 August 1945.
NHK was then known as the Japan Broadcasting Corporation and served as Japan’s national broadcaster. Its staff recorded the emperor’s rescript inside the Imperial Palace on the night before the announcement and prepared the recording for nationwide transmission.
The recording was not broadcast immediately after it was made. Palace officials and technicians had to protect the discs during a military crisis, because some army officers opposed ending the war. Rebels attempted to prevent the broadcast during the night, but they failed to locate the recordings and could not stop the message from reaching the public.
At noon on 15 August, NHK introduced the announcement and played the emperor’s voice. Because the language was formal and the recording was difficult to hear, many listeners did not immediately understand that Japan had accepted surrender terms. An announcer helped clarify the significance afterward.