The following version of this book was used to create this study guide: Lauren, Christina. Josh and Hazel's Guide to Not Dating. Galley Books, 2018. Kindle Edition.

The narrative opens with Hazel giving all of the reasons that she and Josh will never date and are not compatible. She first met him in college. Then, years later, they meet each other again at a barbecue hosted by her best friend, Emily, and Hazel discovers that Josh is Emily's brother. Josh has a girlfriend, named Tabitha, who is supposed to be with him, but is not. She has moved from Portland to Los Angeles and says she has to work. In reality, she is seeing another man. Emily suspects that this is the case and Josh admits the truth to himself when Tabitha sends him a message that was meant for her other boyfriend. He goes to Los Angeles to talk to her about their relationship.

In the meantime, encouraged by Emily, who thinks that Josh needs to learn how to have fun, Josh and Hazel have begun to do things together. Hazel's apartment floods just when Josh is ready to go to Los Angeles. He lets Hazel stay in his home while he is away. However, he returns early because he and Tabitha end their relationship. Hazel continues to stay in his home because she cannot return to her apartment, yet. One night Hazel and Josh talk about dating. They agree to go on double dates with someone each one chooses for the other.

The matches are bad for both Josh and Hazel. One of Josh’s dates implies that he should be on a date with Hazel instead of her. One double date results in the matches going home with each other. One match tells Hazel that she is not compatible with him. Two other potential partners have dated each other before, leave Josh and Hazel to have sex with each other, and then have a fight.

The dating situation and Josh’s and Hazel’s relationship become more complicated when Josh and Hazel break their vow not to have sex with each other. They tell each other that nothing has changed, however Josh begins to admit to himself that he has romantic feelings for Hazel. Hazel has always had them for Josh, but does not feel as if she is compatible with him. She fears that if they start dating, they will break up and she will lose him as a friend as well.

Josh shares his feelings about Hazel with Emily. Emily tells him that he cannot hurt Hazel because doing so would break her. Hazel and Josh decide to resume their double dating. This time it is Hazel who is set up with her ex-boyfriend, Tyler. They dated in college and he was her first love, however he manipulated her so that she would continue to have sex with him. Now, he seems to regret losing her. The double date ends, and Josh takes his date back to her home. Tyler takes Hazel’s phone number. Hazel wants to talk to Josh when she returns home, but she thinks he is with Sasha, his date for the night. Then Josh comes. They talk and have sex. The next morning, Hazel surprises Josh by behaving in a manner that seems normal. She expresses her fear that would discover that they are not compatible if they were to date each other. He convinces her to fix him the type of breakfast she usually fixes him. Then she receives a text from Tyler expressing a wish to get back together. Hazel asks Josh what she should do. He says that she should give Tyler a second chance. She invites Tyler to her place for dinner.

Tyler arrives on the appointed evening. They are talking when Josh arrives with Sasha. During the evening they decide to go on a double date to a music festival. The event lets Josh see that Sasha is a nice woman, but not the one for him. Hazel also realizes that she and Tyler are not compatible when he calls her behavior embarrassing.

Later, she tells Emily that she loves Josh and knew if for sure when he bought her a funny hat at the festival. While they are together, Emily remembers that she needs to buy tampons and Hazel remembers that she has missed her period for the last two months. Hazel takes a pregnancy test at Emily’s house and discovers that she is pregnant. Josh arrives at Emily’s house later. No one is there and he sees the positive pregnancy test. He thinks that Emily is pregnant. Afterwards, he meets Dave for a drink and realizes that he does not know that Emily may be pregnant. Josh does not tell him, but he does share his feelings about Hazel. Dave says that he should tell Hazel how he feels.

Hazel calls Josh and he goes to her apartment. Both of them say that they have something to tell the other, but they have sex first. Josh worries that he hurt Hazel because she is bleeding. Hazel realizes that her pregnancy is in danger. She decides to go to the doctor. Josh finds the ultrasound results and realizes that Hazel is pregnant, not Emily. He says that he is going to the doctor with Hazel. They go and declare that they are going to stay together no matter what.

At the end of the narrative, readers discover that Josh and Hazel are married and his parents live with them. They have two children and are expecting a third. Their daughter has Josh’s personality. She is the baby that Hazel almost lost and who taught her how to be calm. Their son has her personality. Josh and Hazel marvel at the fact that they are together.