Juno MacGuff is sixteen years-old who after a one-time sexual encounter with her best friend Paulie, learns that she's pregnant. Juno and Paulie like each other, but not enough to start a family, complete with a child. Paulie leaves all the decisions about the baby to Juno. Initially she decides to have an abortion, but can't go through with it. So she decides to have the baby and give it up for adoption.