As high school graduation nears, Wren Gray is surprised to connect with gentle Charlie Parker, a boy with a troubled past who has loved her for years, while she considers displeasing her parents for the first time and changing the plans for her future.

Throughout their senior year in high school, Zoe, Maddie, and Angela continue to share "instant messages" with one another about their day-to-day experiences as they consider college, sex, the importance of prom, and the inevitable end of their inseparable trio.

Through "instant messages," chronicles the struggles best friends Maddie, Angela, and Zoe face during their freshman year in college, each of them in a different state, two wondering if their romantic relationships will last, and one determining that roller derby is the key to keeping the trio close.

Now high school juniors, Zoe, Maddie, and Angela continue to share "instant messages" with one another as one of them experiments with marijuana, another gets her first boyfriend, and the third moves three thousand miles away.