"Why We Broke Up" is a young adult novel by Daniel Handler, illustrated by Maira Kalman. The story follows Min Green, a high school student who is in love with popular athlete Ed Slaterton. The novel takes the form of a long letter from Min to Ed, detailing the reasons for their breakup and returning a box of mementos to him. Each item in the box is described in detail, bringing to life the memories and emotions associated with their relationship. As Min reflects on their time together, she begins to realize the flaws in their relationship and the ways in which they were fundamentally incompatible. The novel explores themes of love, loss, and self-discovery, and it has been widely praised for its authentic portrayal of teenage relationships and emotions. The illustrations by Maira Kalman are an integral part of the book, adding a whimsical and nostalgic touch to Min's narrative.