Content Warning: In general, This One Summer discusses sexuality and includes profanity.

This One Summer begins as protagonist and narrator Rose Wallace, who is 12 years old, is on her way to Awago Beach for the summer with her family. Rose has long, straight hair and wears a hoodie. She looks forward to visiting the place she goes every summer but seems pensive as she stares out the window of the car. Detailed blue-and-white illustrations with vivid shadowing detail her and her surroundings. Rose flops down on her bed at the family cottage as her parents, Evan and Alice, argue over the fact that they are supposed to be on vacation. She almost immediately takes off to see her summertime friend, Windy, using a bike that sits in the shed. Windy is 10, and Rose has known her since she was 5. Windy’s mother, Evelyn, is an older mother and a massage therapist with an eclectic nature. She welcomes Rose, giving her a hug and telling her she smells “like the trees” (21). Windy has short, messy hair and is thrilled to see her friend again.