The Sisterhood of the Traveling Pants is a series of four bestselling young adult novels by Ann Brashares. The novels tell the continuing story of four young girls who acquire a pair of magical jeans that fit all four of them perfectly, even though they're all different shapes and sizes. The four main characters are Lena Kaligaris, Tibby Rollins, Bridget Vreeland, and Carmen Lowell.
The series begins with the four girls' in their sophomore year of high school, and follows them through four summers, finally ending with the summer following their freshman year of college. During this time the girls develop in various ways, but their ultimate goal is to learn to become individuals whilst maintaining their childhood friendship that makes them whole.
Two of the four books were turned into movies starring Alexis Bledel as Lena, Amber Tamblyn as Tibby, America Ferrera as Carmen, and Blake Lively as Bridget.