A big screen adaptation of the smash hit Broadway musical about a teenager named Evan Hansen (Ben Platt) who has a severe anxiety disorder that gets in the way of his connecting with other people.

At high school, he's an outcast who can't even get anyone to sign his cast when he breaks his arm. His therapist asks Evan to write a positive letter each day addressed to himself. But his first day doesn't go as well as he'd hoped and by the time he finishes it, it's not very positive. Just as Evan prints out his letter at school, he bumps into another student, Connor Murphy (Colton Ryan). Connor signs his name across Evan's cast, but then he spots Evan's letter on the printer and takes it.

When Evan learns that Connor committed suicide, he realizes he didn't know Connor at all. The entire school begins to elevate Connor's status, when in fact, Connor was an outcast who had no friends. However, Connor's parents find Evan's letter and assume Connor wrote it, and because it's addressed to Evan, they mistake Evan as his friend. Evan tries to deny it, but when Connor's parents don't listen to his protestations, he goes along with their belief. He discovers that he now has status in his school as Connor's friend and even Evan's longtime crush, Connor's sister Zoe (Kaitlyn Dever), begins talking to him.