Juno MacGuff is not your usual teenager; smart and sharp-tongued, she stands out from the usual high school crowd. After losing her virginity with her friend Paulie Bleeker on a chair, she soon finds herself pregnant. At first she decides to get "a hasty abortion", but can't go through with it and instead decides to find a suitable couple to adopt the baby. Searching through ads in The Pennysaver she comes across the Lorings, an affluent suburban couple, and agrees to allow them to adopt the child. As she falls more and more pregnant she begins to bond with Mark Loring, a failed musician turned commercial jingles writer, over horror films and music, while staying a little apprehensive about Vanessa, his highly strung wife.