When seventeen-year-old Callie Christianson answers the doorbell, she never expects to find her ex-best friend, Egan Pasko, there with flowers. Their childhood friendship ended their freshman year when he shut her in a locker and walked away. But now he's sorry and he'd like to take her on twenty-one dates to prove it. It's an experiment, he says, to see if two people who used to be "just friends" can fall in love. And, of course, they'll record the whole thing and put it online to see how many views they can wrangle out of it.

Callie's ready to tell him to get lost. Until she realizes Egan's crazy, stupid idea could help her gain the followers she needs to earn the mentorship opportunity that will launch her baking career. So the dates begin. And, even though nothing goes according to Callie's plan, all the time spent with Egan is reminding her of everything she used to love about him.

The only problem is their viewers aren't falling in love with her. The haters come out in droves to tell her exactly how terrible they think she is. The only thing keeping Callie in the experiment is Egan's hints that he might be starting to fall for her. Except she can't be sure he's not playing it up for the sake of the camera.

Then Egan shares the most vulnerable parts of Callie's life story online without her permission, stunning her into a shame spiral and leaving her to fend for herself in the comments. With their friendship once again at stake, will Callie walk away for good? Or is her heart too involved to let Egan go?