Joe Brady (Gene Kelly) and Clarence Doolittle (Frank Sinatra) are Navy sailors who have a four-day leave in Hollywood. Joe has his heart set on spending time with his girl, the unseen Lola. Clarence, the shy choir boy turned sailor, asks Joe to teach him how to get girls. Donald, a little boy who wants to join the navy, is found wandering around the boulevard by a cop, who takes him to the police station. Clarence and Joe end up being picked up by the cops to help convince Donald to go home. After the two sailors wait at home and entertain Donald, Donald's Aunt Susie arrives. Clarence is smitten with her from the beginning. Susan goes on to tell them that she has been trying to find work in music, and longs to perform with José Iturbi. Trying to make Susan impressed with Clarence, Joe tells her that Clarence is a personal friend of Iturbi, and that he has arranged an audition for Susan with him. That night, they go out to a cafe (on an MGM recreation of Olvera Street) where Clarence meets a girl from Brooklyn, and they hit it off. The next day, Joe visits Donald's school, and tells the kids the story of how he got his medal, and how he brought happiness to a lonesome king (played by Jerry Mouse from Tom and Jerry, with Tom Cat briefly appearing as a servant), and joy to the forest animals of the kingdom.