Heartstopper tells the story of two protagonists who are on intersecting paths. One, Charlie Spring, is certain of his sexuality but is unsure about many of his feelings and relationships. Though he’s quite popular, a history of being bullied for his sexuality has left him insecure, questioning the motives of those who want to connect with him. And, because he believes himself to be a failure in love, he struggles to understand his intrinsic self-worth. The other, Nick Nelson, is an easy-going, likeable athlete with lots of friends. As the two boys grow increasingly close and Nick’s feelings for Charlie deepen, Nick is forced to consider what it might mean to desire something out of what he considers ordinary: a romantic relationship with a boy. While Charlie grapples with his secret crush on Nick, wondering throughout if he’ll be heartbroken and rejected, Nick wonders whether their relationship will inevitably and irrevocably change him, starting with his very identity.  

Charlie’s timidity stems in part from the bullying he suffered when he came out at school in Year 9. Charlie’s classmates, operating from absurd stereotypes about gender and sexuality, responded to the revelation that Charlie was gay by taunting, threatening, or ostracizing him. In this way, his classmates’ behavior reinforced narrow views of acceptable ways to be a boy and acceptable ways to fall in love, leaving Charlie hesitant to trust the peers outside his trusted circle of friends. Though the bullying stopped in Year 10, Charlie is still traumatized, so much so that when the older Nick greets him outside of class, Charlie’s first reaction is to assume that he is the butt of a joke he doesn’t yet understand. Later, when the entire rugby team reminds Charlie of the boys who bullied him, he’s so disoriented by his own fear and insecurity that he has trouble recognizing the success he achieves on the pitch.  

Charlie’s inability to see his own worth and lovability is most apparent in his relationship with Ben. In the midst of Charlie being bullied, Ben lavished praise on Charlie, calling him brave, and made out with him. At first, Charlie is flattered by the older boy’s attention, excited by what he sees as a budding romance. But Ben keeps their connection a secret, is increasingly demanding of Charlie’s time and affection, and has a girlfriend, all of which leaves Charlie feeling used and unvalued. In contrast, his relationship with Nick helps build his self-esteem, teaching him that he deserves to be more than Ben’s dirty little secret. As Nick praises Charlie and Charlie grows stronger through their friendship, Charlie finds the courage to break up with Ben, clearly articulating the inadequacy of Ben’s behavior and the ways in which Charlie deserves better. When Ben persists in demanding that Charlie hook up with him and attempts to sexually assault him, Nick saves Charlie by physically removing Ben. In the final confrontation with Ben, Charlie stands up for himself vehemently, successfully extricating himself from the toxic relationship with Ben. This process parallels the way that, through his connection with Nick, Charlie develops deeper understanding of his own worth and the strength to demand what he deserves from others.  

Just as Charlie learns to love himself through his relationship with Nick, Nick gains a better understanding of who he is through their relationship. In the beginning of their friendship, Nick’s classmates—and Nick himself—all assume that Nick is straight, often relying on the same limited stereotypes that led to Charlie’s bullying. For example, just as Nick’s rugby teammates think Charlie can’t play sports because he’s gay, Charlie’s friend Tao also assumes Nick can’t be gay because he’s an athlete. As Charlie and Nick grow closer, especially after they spend time together at each other’s houses, Nick notices that his feelings for Charlie are romantic. This causes him to question his sexual identity. Hesitant to speak about his confusion aloud, he turns to Google, hoping for the kind of concrete answers that only come through soul-searching. Though he’s confused about his feelings, he remains connected to Charlie, and their friendship continues to deepen, with both boys harboring secret feelings.  

The romantic tension of the novel comes to a head at Harry Green’s birthday party. There, Nick is confronted with perceptions of the person he used to be. This is illustrated through his friend Harry, who remembers a crush he had on their mutual friend Tara three years ago and demands that Nick pursue her. Harry’s aggressive insistence that Nick connect with Tara pulls Nick away from where he wants to be, with Charlie. This illustrates the ways that, throughout the novel, assumptions of Nick’s straightness cause distance between him and Charlie, making it difficult for them to take their relationship to the next level. After Tara comes out to Nick and opens the door for him to talk to her about his sexuality, Nick confronts Harry, telling him off, rejecting the conventional ideas about who he is, and striking out on his own path. At the same time, Charlie is confronting Ben for the final time, suggesting that they are both breaking with their limiting pasts, creating space for something new. Reunited, the two boys finally kiss, expressing physically the romance and affection that has been building between them for the entire novel. However, when Nick’s friends come looking for him, Nick runs, leaving Charlie alone and heartbroken. This suggests that there aren’t easy answers for either protagonist, and that they will continue to explore their twinned evolutions in the future.