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).