Four best friends (Tibby, Lena, Carmen & Bridget) who buy a mysterious pair of pants that fits each of them, despite their differing sizes, and makes whoever wears them feel fabulous. When faced with the prospect of spending their first summer apart, the pals decide they'll swap the pants so that each girl in turn can enjoy the magic.

Four young women continue the journey toward adulthood that began with "The Sisterhood of the Traveling Pants." Now three years later, these lifelong friends embark on separate paths for their first year of college and the summer beyond, but remain in touch by sharing their experiences with each other.