The failed Japanese military coup on the eve of Hirohito’s surrender broadcast was the Kyūjō incident.
The attempted coup began during the night of August 14–15, 1945. Officers opposed to surrender seized parts of the Imperial Palace in Tokyo and tried to prevent the recorded imperial announcement from being broadcast. They searched for the recording and sought support from senior commanders, but they failed to obtain decisive backing.
The recording of Hirohito’s speech had been made on August 14 and hidden inside the palace. Palace officials preserved it through the night, despite the danger that the rebels might find it. The coup collapsed after the rebels’ commander, Major Kenji Hatanaka, could not secure the cooperation needed to control the Imperial Palace and national broadcasting facilities.
Hirohito’s recording was broadcast shortly after noon on August 15. The incident is also called the Imperial Palace incident. It is distinct from the February 26 Incident of 1936, another failed coup attempt by Japanese army officers.