In 1929 Chicago, during the height of the Prohibition era, two struggling musicians, Joe and Jerry, witness the infamous Saint Valentine's Day Massacre. Finding themselves in a precarious situation after accidentally observing the mob hit, they become targets of the ruthless gangster Spats Colombo. Desperate to evade the mob and leave the city, they exploit an unconventional escape plan. Joe and Jerry disguise themselves as women, adopting the personas of Josephine and Daphne, and join an all-female band that is en route to sunny Miami for a gig.

Their journey takes a complicated turn when Joe, as Josephine, becomes infatuated with the band's beautiful and naive singer, Sugar Kane. Meanwhile, Jerry, as Daphne, attracts the unlikely attention of a smitten millionaire, Osgood Fielding III. As the two friends navigate their respective romantic pursuits and maintain their facades, they must also continue to dodge the ever-looming threat of the Chicago mobsters. The ruse becomes a precarious balancing act of identity, desire, and survival in a situation that grows increasingly wild and unpredictable.