Scott Pilgrim lives in Canada, is 23, and is dating a high school girl. However, he begins to have dreams of another woman, who he soon meets at a party. In an attempt to speak with her, he confesses he has been dreaming about her. Scared, she runs off. Scott learns her name is Ramona Flowers.

In order to get another chance at meeting her, Scott orders some cds off of Amazon (Ramona delivers Amazon orders). She confesses that he has been dreaming about her because she's been using a subspace highway to make her deliveries that happens to pass through his head. Scott asks her to hang out, and she agrees.

The date gets snowed out, so they return to Ramona's. In order to warm up, Ramona holds Scott. They kiss, and then get under the covers of her bed, but nothing happens. Scott stays the night. The next day Scott's band has a gig. Ramona goes, but during their performance, a man parachutes in and picks a fight with Scott (he has been sending threatening letters throughout the book). He is, evidently, Ramona's ex-boyfriend. She has seven of them, they are evil, and Scott must defeat them all if he wants to date her.

Scott wins the fight against Matthew Mattel, and the book ends with them agreeing they want to go out with each other.