Plot

Hyperactive teenager Judy Foster (Jane Powell) challenges, and is challenged by, her overly-proper parents, pesky brother Randolph (Jerry Hunter), and boyfriend Ogden "Oogie" Pringle (Scotty Beckett).

The upper-class Pringles and middle-class Fosters are two Santa Barbara families. Widowed businessman Lucien T. Pringle's (Leon Ames') interests, including a bank and a radio station, keep him absent from his children's lives. Melvin Colner Foster (Wallace Beery) owns and operates a seafood packing plant, an offshoot of his days as a fisherman. Unlike Lucien, Melvin is very present in his family's lives. Judy Foster (Jane Powell) and siblings Ogden "Oogie" Pringle (Scotty Beckett) and Carol Pringle (Dame Elizabeth Taylor) are seniors at the local high school and have known each other all of their lives. Judy, the school's songbird, and Oogie, conductor of the school's orchestra, are musical collaborators and consider themselves more than friends; Judy and Carol are best friends, although Judy and Oogie are oblivious to Carol's actions being in her best interest, often at their expense. Events before, during, and after the senior-class dance have major repercussions: on Carol's advice, Judy's last-minute escort is Stephen I. Andrews (Robert Stack), nephew of local druggist "Pop" Sam Scully (Lloyd Corrigan). Stephen, a war veteran in town for the summer earning college money as Pop's soda jerk, becomes Judy's new love interest, although she's unaware whether it's just to make Oogie jealous or if it's an idolization of an older man. Carol falls for him too and does whatever she can to "steal" him from Judy without Judy even knowing. But Stephen is aware of the rivalry and knows about Carol's entitled nature and the probable reason behind it. Oogie tries to win Judy back by following the advice of people he trusts. What happens amongst this quartet is complicated by a misunderstanding about Melvin's 20th Anniversary surprise for his wife Dora Foster (Selena Royle).—Huggo

In Santa Barbara, California, teenager Judy Foster and her friends are rehearsing songs for their high school dance when the student director of the show, Carol Pringle, complains that the songs, as performed, are too "juvenile." Carol, a senior at the school and a renowned wealthy snob, demonstrates how the music should be played, and gives the song a more seductive flavor.

Later, Carol tells Judy that famous band leader Xavier Cugat will be the guest of honor at the dance, and urges her to wear her pink dress for the occasion. When Judy learns that her sweetheart, Ogden "Oogie" Pringle, who is Carol's brother, has decided not to take her to the dance, she becomes infuriated and vows to break off her friendship with him. Dejected, Judy visits Pop's Soda Fountain, where she meets Pop's handsome nephew, Stephen I. Andrews. Judy falls instantly in love with the older Stephen, and he agrees to take her to the dance as a favor to Pop.

At the dance, Oogie sees Judy with Stephen and becomes jealous. While Oogie tries to divert Judy's attention away from Stephen, Stephen meets Carol and believes he has found "the most beautiful girl in Santa Barbara." After the dance, Carol tries to help Oogie and Judy get back together by telling Judy that she has convinced her wealthy father to give Judy and Oogie a program on his radio station.

Meanwhile, Rosita Conchellas, a Latina dance instructor, secretly meets with Judy's father Melvin to teach him the rumba, which he hopes to dance on his wedding anniversary. When Oogie tries to make amends with Judy at a dinner arranged by Carol, a misunderstanding arises that leads to his being further alienated from his sweetheart. Judy, however, shows no signs of a broken heart, and later tells her father that she is in love with Stephen and that she intends to marry him. When Judy discovers Rosita's skirt caught in the closet door of her father's office, she incorrectly concludes that her father is having an affair.

Determined to save her parents' marriage, Judy runs home and gives her mother a beauty makeover to make her more appealing to her father. Oogie, in his tireless determination to reunite with Judy, tries to serenade her, but another misunderstanding arises and the plan is spoiled. Judy becomes convinced that her father is planning to leave her mother when she and Carol see him escorting Rosita to his car. Carol and Judy later accuse Rosita of breaking up Judy's home. Rosita misunderstands the accusation and believes that they are talking about Cugat, her fiance. When Judy and Carol finally realize their mistake, they apologize to Rosita. Judy then reconciles with Oogie after she learns that Carol and Stephen are in love, and Stephen agrees to resume his romance with Carol in a few years, when she is older.