In 1988 Seattle, Washington, Lakewood High School valedictorian Diane Court tells her indifferent classmates that the future is optimistic, but frightening. Diane’s intelligence has alienated her from her peers, and her wealthy, divorced father, James Court, is her only friend. Unknown to Diane, her classmate, Lloyd Dobler, is smitten with her. Lloyd and his sister, a single mother named Constance, live without parents in a modest apartment where Lloyd aspires to be a kickboxer rather than a college student. Lloyd’s confidantes, Corey Flood and D. C., insist that Diane will never be interested in dating him, but Lloyd summons the courage to telephone her, and leaves a message with her father. However, James is distracted by another call reporting that Diane has received an exclusive fellowship to study in England. James rushes to his business, a retirement home called “Golden Seasons,” to share the news with Diane, who works in the kitchen. The girl is pleased, but fearful of flying abroad on an airplane. Sometime later, Diane returns Lloyd’s call and reluctantly agrees to join him for a graduation party that evening. There, Lloyd is elected “keymaster”; he must remain sober and hold on to the partygoers’ car keys until he deems them safe to drive. As Lloyd collects keys and keeps an eye on Diane from afar, his friend Corey sings sixty-five lovesick tunes about the betrayal of her former boyfriend, Joe. At the end of the night, Corey has resolved to rid herself of Joe once and for all, and Lloyd is forced to escort an intoxicated classmate home; however, the boy forgets where he lives, and the friends are on the road past dawn. When Diane finally returns home, Lloyd declares his intention to see her as much as possible before she leaves for England. Their next date is a Court family dinner party. Lloyd is astonished by Diane’s bond with her father, and explains his dream of becoming a kickboxer. During the party, Federal Bureau of Investigation (FBI) agents arrive at the door unexpectedly and announce that James is under criminal investigation for tax fraud. Diane later asks her estranged mother to defend James. When Lloyd visits Diane at work, he entertains the elderly residents with a presentation of the film Cocoon. Diane makes love with Lloyd, and in turn receives a letter in which he declares his love, but she abruptly ends their relationship, feeling obliged to spend more time with her jealous and troubled father. Following James’s advice, Diane gives Lloyd a pen as a parting gift. Devastated, Lloyd cruises the streets at night and seeks advice from bachelor friends who loiter in a convenience store parking lot. He leaves messages on Diane’s telephone answering machine, and when she overhears him ask her to destroy the love letter, she picks up the receiver. However, Lloyd has already hung up. On another occasion, Lloyd serenades Diane with the song they first made love to, holding a portable stereo above his head. Sometime later, James buys luggage for his daughter and flirts with the saleswoman, only to discover his credit cards have been cancelled. Diane appeals to an Internal Revenue Service (IRS) officer, who reports that James has been found guilty of defrauding residents in his retirement home by illicitly appropriating their life savings after they die. Returning to an empty house, Diane pries open a locked box to find stacks of $100 bills. She races to “Golden Harvest” and confronts James, who argues that he took the money to finance Diane’s future. He claims to be providing a service to the aged, taking better care of them than their own families, but Diane is enraged by the betrayal. She reflects that she can “say anything” to her father, and identifies James as a crook and a liar. She then goes to Lloyd’s kickboxing studio. The boy is so surprised to see Diane, he is knocked down by his opponent. As Lloyd nurses a bloody nose, Diane apologizes and admits her father’s deceit. She declares her love for Lloyd and takes up residence at his apartment. Sometime later, James is sent to prison and Lloyd insists that Diane visit her father before they leave together for England. However, Diane refuses to get out of the car, so Lloyd hand-delivers a letter. As visiting time ends and James loses hope of making amends with his daughter, Diane appears. She hesitantly admits that she still loves her father and gives him a pen as a parting gift, inviting him to write letters. On the airplane to England, Diane is petrified, but Lloyd assures her that the pending “ding” of the deactivated “non-smoking” sign will indicate their safety. The couple clutches each other through the turbulence of lift-off as the bell finally chimes.