13 Reasons Why (Season 1)

Clay Jansen finds a box filled with audio tapes that was left on his doorstep. By including the first one in his father's boombox, he realizes that the tapes were recorded by his recently deceased classmate Hannah Baker. He accidentally falls and breaks a boombox when his mother enters his room. Clay steals the player from his friend Tony to continue listening to tapes. He listens to the first tape in which Hannah talks about her experiences that led her to suicide. She begins by sharing the story of her first kiss with Justin Foley, who inadvertently spreads an obscene rumor that has affected future events in her life, which is why she begins to think about suicide. Clay’s memoirs show him falling in love with Hannah and working with her at a local movie theater. We also learn that Hannah has appointed her friend Tony to be responsible for distributing the tapes.

Hannah recalls her friendship with two other new students: Jessica, who often moves because her father works in the Air Force and Alex, whom they met in a cafe. Jessica and Alex start dating and stop spending time with Hannah. When Alex breaks up with Jessica, she publicly blames Hannah for it. In the present tense, Hannah's mother, Olivia, finds a note in her daughter’s textbook that leads her to believe that Hannah was intimidated. Clay learns from Jessica about the tapes, with the result that Bryce Walker's peer circle meets to discuss how Clay listens to Hannah's tapes.

As Clay tries to pursue a romantic relationship with Hannah, her relationship with her classmates is threatened by a “Best / Worst” list compiled by Alex Standell, who set a “target” for Hannah. In the present tense, Hannah's mother, Olivia Baker, is trying to track down the school principal to talk about her suspicions of bullying her students and makes a disturbing discovery. In the midst of his investigation, Clay turns to Alex for answers, who not only regrets his actions described on cassettes, but also warns Clay not to trust Tony. Later, Clay accidentally witnesses how Tony and his brothers brutally beat a man. While Justin is trying to recover from his recent fall, Bryce competes in the speed of drinking alcohol with Clay and Alex in the alley.

Hannah hears someone outside the window and confesses to her friend Courtney that she is being watched. Courtney offers to help her catch the criminal in the act. While awaiting the arrival of the pursuer, intoxicated, they begin to play the game "Truth or Action", which leads to a kiss between them. The persecutor, school photographer Tyler Dawn, takes a photo of the girls and sends it to all school students, which leads to the breakdown of the friendship between Courtney and Hannah. Courtney begins to try in every possible way to hide who is the second girl in the photo made by Tyler. In the present tense, Clay comes to Hannah’s house to talk to her mother, but he cannot confess how close he and Hannah were. He is also trying to find out from Tony why he and his brothers beat that man. Tony told Clay that people sometimes have to do their own justice and proves that he has another duplicate of tapes. Inspired by this, Clay takes a naked shot of Tyler and also sends it throughout the school, in revenge for Hannah.

Courtney, fearing that her classmates will find out about her sexuality, begins to spread rumors that the girls in the photo are Hannah and Laura, who is an open lesbian. Courtney also adds rumors about Hannah and Justin, further worsening Hannah's already poor reputation. In the present, Clay forcibly leads Courtney to the tomb of Hannah. She does not reach the grave, because she was ashamed of Hannah for not admitting to her about her sexuality in life. Tony arrives with Clay’s bike and gives him a cassette with a song to which she and Hannah danced at the Winter Ball. Later, Justin, Zach and Alex force Clay to get into the car with them, stealing his bicycle, and accelerate to a frantic speed, thereby frightening him from behind the cassettes. They are stopped by the police, but not arrested, because the officer, as it turned out, is Alex's father. Clay cheats on his mother that he knew Hannah. However, he asked her to represent the school in a lawsuit arranged by the Bakers.

On Valentine's Day, Hannah's date with Marcus did not go as intended, due to rumors about her illegibility in sexual relations. In the present tense, Alex is embroiled in a fight with Montgomery de la Cruz and they both have to stand trial in school. Clay helps Shary with her homework and they almost get close, but Sheri stops because she wants Clay to love her, despite her role in Hannah's death.