Clay Jensen comes home to a mysterious box with his name on it in the front of his house. He finds some cassettes inside the box who were recorded by a girl named Hanna Backer who he had a crush on. He never got to tell her how he felt because she tragically committed suicide. The tapes got passed down to Clay based on the instruction that Hannah gave in them. Hannah gave Tony, her closest friend, who listened to them and ran to her house right away. When Tony arrived he found out that she had already committed suicide and he was too late.
In the tapes Hannah talks about thirteen reasons why she committed suicide. Each tape has two sides where she talks about one person on each. As the Clay listens to the tapes he begins to feel very guilty and wants the people who hurt Hannah to pay for what they did, especially Brice who was the one who pushed her to the edge. Soon Clay will find out that he is in the tapes as well and he was one of the reasons. How will Clay react? What will Clay do with the tapes?