Will Grayson, Will Grayson tells the story of two guys who have the same name - there are two guys called Will Grayson living nearby. They do not know each other, and their lives are pretty different: one of them has a stable family, with two surgeon parents and a gay best friend; the other Will Grayson lives with his mum, needs pills for his mental health issues, does not want any friends and has a big secret. Eventually their lives intertwine in the most unexpected circumstances. Will Grayson, Will Grayson is a book about love, friendship and finding one's sexuality.
As you have probably already noticed, it is written by two different authors, who have tremendously different writing styles. They write alternate chapters, each of which is about a different Will Grayson. This means that each author writes only about one of the Graysons, following the order Green, Levithan, Green, Levithan... This makes the book and the characters so much richer, because the writing of the authors is as different as the two main characters, shown through the 1st person narration.