The author of The Sisterhood of the Traveling Pants was Ann Brashares. She got the idea for the novel from a friend who talked about sharing a pair of pants with friends over one summer. The main characters are four friends - Tibby, Lena, Carmen, and Bridget. Over their first summer apart, they share a magical pair of pants that allows them to feel connected to each other as each girl has an adventure while wearing the pants.