Before The Summer I Turned Pretty became a worldwide smash success, we fell in love with Belly, Conrad and the residents of Cousins Beach through the trilogy of novels with the same name. Written by Jenny Han, who also serves as the show’s creator and executive producer, The Summer I Turned Pretty novels follow the story of a girl and two brothers experiencing first love, heartbreak and summertime magic.
The books were written consecutively in 2009, 2010 and 2011, but like many book-to-television adaptations, the series doesn’t follow the exact storyline of its source material. Of course, considering the show was created over a decade later, there were inevitably elements that needed adjustments to fall in line with today’s standards.
But in case you didn’t read the trilogy before the series came out or if you’re wondering about the differences between the two, keep reading to find out!
There was no debutante ball in the books

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Arguably, one of the biggest changes from the books to the series is the addition of the debutante ball in Season 1. The story in both the books and the show follows Belly Conklin (Lola Tung) as she becomes a young woman, which is exactly what Han wanted to show with the debutante ball.
“The Deb Ball was a chance to really bring a ceremonial rite of passage of growing up to life,” Han said. “To really see that visualized, because I think different cultures have many different ways of marking that moment between girlhood and adulthood. And that’s what Deb Ball is, you’re coming out and being seen as an adult.”
Steven’s role got bigger on screen

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In the series, Steven, who is portrayed by Sean Kaufman, has a much larger role than he does in the books. The written story focuses solely on Belly and her journey, while the series explores the lives of other characters.
In the books, Steven has a minor presence early on in the story, but soon leaves to go on a college tour. The show, however, retains Steven as a main character for its entirety. We also get to see him fall in love on screen, something that never happened in print.
Susannah & Laurel’s friendship gets more love in the show

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The Summer I Turned Pretty series showcases the loving friendship between Susannah (Rachel Blanchard) and Laurel (Jackie Chung), and features dozens of moments between the two. In the books, however, Susannah and Laurel’s friendship isn’t focused on nearly as much.
Throughout Season 1, fans get to see the loving bond between the best friends and how they support one another through anything and everything. Han spoke about adding more of their relationship into the series, explaining it was a necessary change.
“I would say the relationship between the two women, Laurel and Susannah, was foundational to the whole story, because they created [the house at Cousins Beach] for themselves and their kids to have,” Han shared. “It’s almost like this separate time and place. It is a magical place. I think as you grow up, you realize how rare that is to find. To say, ‘I value my time with you in the summer and in Cousins, and we’re gonna do that every single year,’ it is a big deal. I wanted that to come across, that they put this relationship and this time first in many ways. They value that.”
The books are more PG than the show

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Although The Summer I Turned Pretty series isn’t exactly rated for a mature audience (it’s designated TV-14), it does include more mature themes than the books. Han wrote the trilogy for a much younger audience, likely ages 11 and up, while the series was adapted for slightly older viewers.
The series embraces a diverse cast

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In the books, Han never explicitly addresses the ethnicities of any of the characters. But when it came time to cast the show, the showrunner decided to lean into a refreshingly diverse cast.
“When I was approaching the adaptation, I wanted to really reflect the moment that we’re living in,” she shared. “And I think the diversity of characters is a piece of that, so it felt like a really great opportunity to showcase different kinds of talent.”