The Summer I Turned Pretty trilogy is a coming-of-age series that deals with love, young adulthood, and grief. During the first book, it's revealed that Belly harbors a lifelong crush on Conrad Fisher, the oldest brother of the Fishers. The two get together at the end of The Summer I Turned Pretty, the first book in the series, but break up in the sequel, It's Not Summer Without You.

Jeremiah "Jere" Fisher is the younger Fisher brother, who reveals he has feelings for Belly at the end of It's Not Summer Without You. Although Conrad and Belly's relationship is shaky throughout the second book, she flees her hometown to convince him not to abandon college when his beach house is in jeopardy of being sold. By the end of the sequel, Jeremiah and Belly began dating.

Between books one and two, Fisher matriarch Susannah "Beck" Fisher dies of cancer, leaving both her family and the Conklins devastated. Mr. Fisher begins cheating on his wife after her cancer diagnosis and falls into alcoholism after her death. He attempts to sell the summer house in It's Not Summer Without You but is stopped just in time by Belly's mother, Laurel, and Conrad.

The third book, We'll Always Have Summer, takes place two years after the second book.

While at college, Jeremiah cheats on Belly with a sorority girl, leaving her heartbroken. The pair tentatively reconcile and become engaged at a young age. Conrad admits he has secretly harbored feelings for Belly despite her serious relationship with Jeremiah after Belly comes to stay at their summer house.

Conrad also learns that Jeremiah cheated on Belly at his bachelor party, and they get into a fight. Jeremiah and Belly break up for good, but it is revealed in the epilogue that Conrad begins writing Belly letters. The pair reconcile, and Conrad attends her college graduation, where they get back together and eventually marry.

Seasons 1-2 of The Summer I Turned Pretty are now streaming on Prime Video.