Elena Greco, a 60-year-old author, recalls the early years of her friendship with Lila Cerrullo in 1950s Naples when Elena and Lila were two very different girls in their class. As Lila has disappeared, Elena thinks back on those times.
As the end of the fourth-grade approaches, Elena and Lila battle with their families for the opportunity to continue their education. An out-of-town vacation turns into an unforgettable day for Elena. As a death incident occurs in the neighborhood, everything changes forever.
When the girls' interactions with the other sex start to happen more frequently, Lila takes a position against the Solara brothers. Elena struggles with the onset of puberty, her academics, and her friendship with Lila, who works with her family.
Stefano Carracci sends an invitation to Elena, Lila, and their families for New Year's Eve. As Elena starts high school, she makes a promise to keep ahead of Lila both academically and romantically.
Elena grows weary of Gino, and Lila chooses to reject two potential suitors at great expense. An unusual journey to the metropolis becomes violent. After accepting an invitation to spend the summer away from town, Elena is worried about not being there for Lila.
Elena runs into the Sarratore family on the island of Ischia, rekindling her adolescent infatuation with Nino. Lila's resistance to Marcello's persistent courtship approaches a critical point. On the occasion of her 15th birthday, an unexpected encounter leaves Elena feeling uneasy.
Elena returns to Naples to discover that Lila and Stefano have developed a romantic relationship despite Marcello's continued presence.
In order to boost the sales of Cerullo shoes, Stefano strikes a contract with the Solara family. Nino then prods Elena to write an article for his magazine about her experience after she is expelled from class for speaking her mind.