A teenager by the name of Christine McPherson, who usually goes by her nickname Lady Bird, has just finished touring a series of Californian colleges. She is now being driven back to her home in Sacramento by her mother, Marion. After graduating, she intends to apply to schools outside of California, discontent with the boring life she leads. Marion, believing Lady Bird to be ungrateful, does not agree with her decision and swiftly rebukes her. Lady Bird, deciding she would rather throw herself out of a moving car than suffer her mother’s interminable lectures one second longer, proceeds to do just that.
Two close childhood friends, Amy and Molly, are about to graduate from high school. After graduating, Amy plans to travel to Botswana for a few months while Molly has been admitted to a prestigious school. The two of them have a reputation for being overachievers, choosing not to party and instead focusing on their studies. While using a restroom, Molly overhears her peers making fun of her. Molly then realizes that she and Amy didn’t have enough fun in high school and should use the remaining time before graduation and go to an end-of-year party being held by a popular kid named Nick.