The Zero Hour was the brainchild of Major Shigetsugu Tsuneishi, who joined the Japanese Imperial Army's 8th Section G-2 (Psychological Warfare) unit as the Army representative to the Information Liaison Confidential Committee, which oversaw the coordination of the nationalized news agencies, in November 1941. His first effort was a propagandistic photographic magazine called Front, based on the format of the American magazine Life.
Major Tsuneishi established an office at Radio Tokyo (NHK) and issued orders to the NHK Overseas Bureau's American, European, Asian, Editorial and Administration Divisions through Bureau Chief Yoshio Muto. Thereafter, all news broadcasts became official announcements of the Japanese Imperial Army General Headquarters (GHQ). The American Division radio announcers section was headed by Yuichi Hirakawa, a native Japanese with a degree in Dramatics from the University of Washington.
Tsuneishi acquired a veteran radio announcer with the capture of Australian Army Major Charles H. Cousens, who had been a popular and highly regarded news commentor in Sydney before the War. During an interrogation at the General Staff HQ in Tokyo on August 1, 1942, Tsuneishi made it clear to Cousens that he had to broadcast for the Japanese or face execution before putting him to work at 6 p.m. that same evening. Cousens was subsequently tasked with writing and broadcasting "radio essays" on the need to have high ideals as a human being, collections of platitudes with no propaganda value.
On October 15, 1942, Cousens was joined at Radio Tokyo by American Army Captain Wallace "Ted" Ince and Philippine Army Lieutenant Normando Ildefonso "Norman" Reyes, both captured at Corregidor, where they'd been in charge of the "Voice of Freedom" Allied propaganda broadcasts. Ince produced "From One American to Another" and Reyes "Life in the East" under the direction of Japanese Army overseers.
In 1943, the Japanese Army developed facilities to monitor medium-wave radio domestic broadcasts from the U.S., allowing them to pick up news of local disasters such as floods in Mississippi, forest fires in California, major automobile accidents and train wrecks. Major Tsuneishi decided to have his POWs broadcast a news program of such items to demoralize front-line U.S. troops. The show would be called the Zero Hour and contain only true items that had been censored from Allied news broadcasts.
The first broadcast of the Zero Hour was made at 5:15 p.m. on March 31, 1943 and consisted of a 15- to 20-minute program of jazz, popular music and news delivered by Norman Reyes, beamed on the 19- and 25-meter shortwave bands.
The Zero Hour literally made headlines on June 29, 1943, when The New York Times carried the first American report of its activities: "Between the Tokyo radio and Japanese bombers, the nights are not always dull here. Tokyo has been beaming a program called the 'Zero Hour' direct to the Russell Islands and Guadalcanal. The fellows like it very much because it cries over them and feels so sorry for them. It talks about the food that they miss by not being home and tells how the war workers are stealing their jobs and their girls."
Major Tsuneishi was pleased by this report and in August 1943 expanded the program to 40- to 45-minutes, with Major Cousens reading POW messages, Captain Ince reading U.S. news items and Lieutenant Reyes playing records with commentary. The news was compiled by NHK Nisei staffers Kenkichi Oki and George Mitsushio, but the POWs tried to subvert the propaganda wherever possible by reading it with a joking tone or by rushing through objectionable items.
On November 11, 1943, the Zero Hour was expanded again, to 75 minutes starting at 6 p.m. Tsuneishi also requires the addition of a female broadcaster to give the program more appeal to war-weary troops and to increase the nostalgia factor. Fearing that their efforts to undermine the propaganda value of the program will be exposed by the addition of an outsider, the POWs are in a quandry until Cousens requests that Iva Toguri, an NHK typist who had befriended the POWs and was outspokenly pro-American in her views, be conscripted as the female announcer instead one of the regular female staffers.
George Mitsushio objected, "You can't use a voice like that!" Nisei staffer George Kazumaro "Buddy" Uno asked, "What's the idea? Why pick a farmer like Iva? No experience. Terrible voice. Even her English is not laudable." But Cousens prevails, citing similarities to the popular Gracie Allen, Shirley Booth and Marian Driscoll (the Molly of "Fibber McGee and Molly"). Cousens' plan was to take lemons and turn them into leomonade by using the female broadcaster foisted onto the POWs by their Japanese bosses to sabotage the Zero Hour by making a complete burlesque of it.
Iva Toguri began broadcasting without anonymously, not wanting to identify herself by name. Informed that she must have some distinctive sobriquet for the benefit of the audience, she called herself "Ann" from the abbreviation ANN for "Announcer" in her scripts. Later, when she became more comfortable with what she and the POWs were doing, she got into the swing of it and became "Orphan Ann" in a dual homage to "Radio Orphan Annie" and the popular phrase "Orphans of the Pacific" used to describe her audience, the Allied troops.
On November 13, 1943, the new Zero Hour broadcast format was finalized: 75 minutes, broadcast from 6 to 7:15 p.m. 18:00-19:15, seven days a week. It opened with "Strike Up The Band" by Arthur Fiedler and the Boston Pops, followed by 5-10 minutes of 25-word POW messages read by Major Cousens. "Here comes your music!" was his introduction to Iva Toguri's 15-20 minute D.J. segment, in which she played three 33.3-RPM 12" or four 78-RPM 9" records, prefaced by comments scripted for her by Cousens. The music was mainly semi-classical or classical, with a few dance recordings, and Iva's voice was on-air about 2-3 minutes. Next was "American Home Front News" read by Captain Ince from a script by George Mitsushio (5-10 minutes), the 15-20 minute "Juke Box" pop music & jazz D.J. segment with Lieutenant Reyes, "Ted's News Hightlights Tonight" read by Captain Ince from the NHK shortwave monitors' script (5-10 minutes), an occasional news commentary by Nisei Charles Yoshii (called the "Japanese Lord Haw-Haw") and "Goodbye Now" leading into sign-off by Captain Ince. Iva, Cousens and Ince never worked Sundays; Ruth Hayakawa substituted for Iva and Lieutenant Reyes substituted for Cousens and Ince under the supervision of Kenkichi Oki.
By January 1944, twelve more Allied POWs arrived at the prison camp and more new programs were begun: Three Missing Men, Saturday Jamboree, The Postman Calls, War On War, Enerjocracy, From One American To Another, The Voice Of The People, the Australian Hour, the German Hour and the Civilian Air Program. All had the same general format and content as the Zero Hour.
In December 1944, Zero Hour was shortened to 60 minutes. The program was now considered NHK's Front Line Section and controlled directly by Major Tsuneishi. George Mitsushio was News Analysis Section chief, with Kenkichi Oki in charge of the actual broadcasts, which were mostly propaganda with the notable exception of Iva Toguri's "Orphan Ann" segment.
The final Zero Hour broadcast aired on August 12, 1945, three days after the second atomic bomb destroyed Nagasaki and three day before Emperor Hirohito announced Japan's unconditional surrender to the Allied forces and renounced the Imperial Mandate of Heaven. Radio Tokyo itself was shut down immediately following the Emperor's speech.