The book centers around a high school junior named Simon who is not openly gay and prefers to save his drama for the school musical. However, when an email falls into the wrong hands, his secret is at risk of being thrust into the spotlight. Now, Simon is being blackmailed, and he must step out of his comfort zone before he's outed against his will or worse, the privacy of Blue, the pen name of the boy he's been emailing, will be compromised. As he navigates through friendship, blackmail, and the prospect of love, Simon must find a way to be true to himself while also trying to decode the identity of the anonymous classmate he has fallen for online.

The book follows the interwoven stories of three high school boys as they navigate the complexities of identity, friendship, and love while coming to terms with their sexuality. Jason is a jock struggling with his attraction to men, Kyle is an out-and-proud gay teen who harbors feelings for Jason, and Nelson is Kyle's flamboyant best friend who is also openly gay and advocates for LGBTQ+ rights. As they each face challenges such as homophobia, self-acceptance, and the risk of HIV, their lives intersect in ways that profoundly impact their journey towards understanding and embracing who they are.

In early-2000s Seattle, AJ moves across the country to explore his identity and finds an unexpected chosen family: a tight-knit group of gay Asian friends whose personalities and lives collide in funny, tender, and complicated ways. The novel follows their friendships, romances, and struggles as they navigate belonging, desire, and community against the backdrop of a changing city.