During World War II, American servicemen regularly huddled around radios to listen to the “Zero Hour,” an English-language news and music program that was produced in Japan and beamed out over the Pacific. The Japanese intended for the show to serve as morale-sapping propaganda, but most G.I.s considered it a welcome distraction from the monotony of their duties. They developed a particular fascination with the show’s husky-voiced female host, who dished out taunts and jokes in between spinning pop records.

“Greetings, everybody!” she said during one broadcast in 1944. “This is your little playmate—I mean your bitter enemy—Ann, with a program of dangerous and wicked propaganda for my victims in Australia and the South Pacific. Stand by, you unlucky creatures, here I go!”

American G.I.s concocted a range of exotic backstories for the woman they called “Tokyo Rose,” but few were stranger than the truth. Her real name was Iva Toguri, and rather than being an enemy agent, she was an American citizen who had found her way onto the radio almost by accident. Most fascinating of all, she would later allege that she had remained loyal to her country by actively working to undermine the message of her propaganda programs.

Born on July 4, 1916, Iva Toguri was the daughter of Japanese immigrants who owned a small import business in Los Angeles. She had spent her youth serving in the Girl Scouts and playing on her school’s tennis team, and later graduated from UCLA with a zoology degree. In 1941, her parents sent her on a trip to Japan to help care for an ailing aunt. The 25-year-old Toguri had never been abroad before and quickly grew homesick, but her problems only mounted that December, when a paperwork problem saw her denied a place on a ship home. Only a few days later, the Japanese bombed Pearl Harbor.

WATCH: Tokyo Rose: Victim of Propaganda on HISTORY Vault

With the United States and Japan at war, Toguri found herself trapped in a country that she barely knew. Japanese military police tried to persuade her to renounce her U.S. citizenship and swear allegiance to Japan—a route many other Americans in Japan took—but she refused. As a result, she was classified as an enemy alien and closely monitored. Toguri spent the next several months living with her relatives, but frequent harassment by neighbors and military police eventually led her to move to Tokyo, where she took a secretarial job. By August 1943, she was working as a typist at the broadcasting organization Radio Tokyo.

It was at Radio Tokyo that Toguri met Major Charles Cousens, an Australian military officer who had been captured in Singapore. Cousens had been a successful radio announcer before the war, and he was now being forced to produce the propaganda show the “Zero Hour” for the Japanese. In defiance of their captors, he and his fellow POWs had been working to sabotage the program by making its message as laughable and harmless as possible.

After befriending Toguri, who occasionally smuggled supplies to him, Cousens hatched a plan to use her on air as a radio announcer. “With the idea that I had in mind of making a complete burlesque of the program, her voice was just what I wanted,” he later said. “It was rough, almost masculine, nothing of a femininely seductive voice. It was the comedy voice that I needed for this particular job.”

While she was initially hesitant to get behind the microphone, Toguri eventually became a key participant in Cousens’ scheme. Starting in November 1943, her “gin-fog” voice was a recurring feature on the “Zero Hour” broadcasts. Toguri adopted the radio handle “Orphan Ann” and grew adept at reading Cousens’ scripts in a joking manner, sometimes even warning her listeners that the show was propaganda.

“So be on your guard, and mind the children don’t hear!” went one introduction. “All set? Okay! Here’s the first blow at your morale—the Boston Pops playing ‘Strike Up the Band!’” In another broadcast, Toguri called her listeners “my favorite family of boneheads, the fighting G.I.s in the blue Pacific.”

The surviving recordings and transcripts of Toguri’s programs indicate that she never threatened her listeners with bombings or taunted them about their wives being unfaithful—two favorite strategies of wartime propagandists—but she wasn’t Japan’s only lady announcer. There were dozens of other English-speaking women who read propaganda, and at least some of them adopted a more sinister tone.

As the war dragged on, American servicemen began referring to the different female voices by a single, infamous nickname: Tokyo Rose. None of the announcers—Toguri included—had ever used the moniker, yet the character became legendary. “Hers was so persuasive a myth that for most Americans she was as famous a Japanese as Emperor Hirohito,” journalist John Leggett later wrote in the New York Times.

Toguri performed her “Orphan Ann” character on the “Zero Hour” for roughly a year and a half, but she appeared with less frequency in the lead-up to the Japanese surrender in August 1945. By then, she had married a Portuguese-Japanese man named Filipe D’Aquino and was looking to return home. She remained in dire financial straits, however, so when two American reporters arrived in Japan and offered $2,000 for an interview with the famous “Tokyo Rose,” she naively stepped forward to recount her story. It would prove to be a disastrous decision.

Once her identity became public, Toguri was made into the poster child for Japan’s wartime propaganda and was arrested on suspicion of treason. She would remain in custody for over a year until a government investigation concluded that her broadcasts had been nothing more than “innocuous” entertainment.

Toguri made an attempt to return home after her release, yet anti-Japanese sentiment in the United States remained high. Several influential figures—among them the legendary radio commentator Walter Winchell—began lobbying the government to reopen the case against her. The campaign worked, and in 1948 Toguri was rearrested and charged with eight counts of treason.

At her trial in San Francisco, Toguri stressed that she had remained loyal to the United States by working to make a farce of her broadcasts. Charles Cousens even came to the United States to testify on her behalf, but the prosecution produced a series of Japanese witnesses who claimed to have heard her make incendiary statements on the air. Much of the case centered on a single broadcast that occurred after the Battle of Leyte Gulf, when she was alleged to have said, “Orphans of the Pacific, you are really orphans now. How will you get home now that your ships are sunk?” The remark, which didn’t appear in any of her show transcripts, proved to be a deciding factor in the case. In October 1949, a jury found her guilty of one count of treason. She was stripped of her American citizenship, given a $10,000 fine and sentenced to 10 years behind bars.

Toguri ultimately spent six years in a women’s prison in West Virginia before being released early in 1956. She reunited with her family, settled in Chicago and began working as an employee at her father business, but her reputation as “Tokyo Rose” continued to follow her. She was forced to fight off a deportation order from the U.S. government, and received no answer from repeated presidential pardon requests.

It was nearly two decades before there was a fresh development in her case. In 1976, two of the key witnesses from her trial admitted that they had been threatened and goaded into testifying against her. “She got a raw deal,” one of them said. “She was railroaded into jail.” Around that same time, the foreman of her jury said that the judge in the case had pressed for a guilty verdict.

With public opinion turning in Toguri’s favor, groups ranging from the California legislature to the Japanese-American Citizens League all endorsed a new petition for a presidential pardon. On January 19, 1977, in one of his last acts in office, President Gerald Ford granted the request. Toguri, who was then 60 years old, was exonerated of treason and restored her American citizenship.

“It is hard to believe,” she said at the time. “But I have always maintained my innocence—this pardon is a measure of vindication.” The woman once known as “Tokyo Rose” later returned to private life in Chicago, where she died in 2006.

READ MORE: How Japanese Americans Fought for—and Won—Redress for WWII Incarceration