Utinsky and Flores had a common interest in gathering supplies to help American and Filipino POWs imprisoned in Camp O'Donnell, located about 110 km (68 miles) north of Manila.
With a half-American, half-Filipina woman named Evangeline Neibert ("Sassy Susie"), Flores returned to O'Donnell several times.
Utinsky persuaded Flores to surrender to the Japanese and claim that she did not know the two men were Americans but had only hired them to guard the beauty parlor.
She realized, however, that she was under suspicion and got permission from the Filipino authorities to move out of Manila to Cabanatuan on the pretext that she was needed to take care of a sick aunt, "Mrs.
Utinsky had become increasingly irascible and leadership of Miss U shifted toward a Spaniard named Ramon Amusategui and his Filipina wife, Lorenza.
Her forged identification documents were accepted as genuine; the Japanese apparently thought they had detained the wrong woman and released her, but security was tightening and her work was becoming more dangerous.
In December Ramon Amusategui ordered deliveries of survival packages of food and money to the Cabanatuan POWs to be halted temporarily because of the Japanese crackdown.
[9] In 1943 and 1944, now living in Cabanatuan, Flores dressed as a peasant woman and set up a fruit and vegetable stand near where American POWs worked daily in the rice paddies.
With contributions of money from Filipinos in Manila, Flores subsidized the merchants so that they could sell items to POWs at cheaper prices and in greater quantity.
Her efforts, and those of many other Filipinos, to get additional food and other supplies into the camp made a life or death difference for POWs.
On 3 May 1944, in a prearranged signal, Flores ran a hand through her hair to tell a POW contact, a cart driver named Fred Threatt, that she had a package for him.
Hartendorp in his 2-volume history, The Japanese Occupation of the Philippines, credits Naomi Flores with being the catalyst for the Miss U Spy Ring.
Two Americans with whom she worked, Peggy Utinsky and Claire Phillips, returned to the United States and achieved fame from books they wrote and movies about their experiences as heroes of the Filipino resistance.