In the Book:
- Clay's thoughts during the thirteenth reason. He's begging the teacher to just stand up and help Hannah, to not simply ignore her pleas for help. But the Foregone Conclusion makes it very clear that he won't help her.
- One of Clay's main roles in the story is really to increase the gravity of the massive Tear Jerker that is this book.
- At one point when he's in the local diner that lead to one of Hannah's reasons, his waiter gives him a free meal after seeing the expression he had on his face after having listened to the tapes.
- The very last tape. Tape 7, side B. The one that supposedly had nothing on it. Nothing but static for a few minutes, and then, Hannah's voice, whispering, "Thank you."
In the Series:
- The simple fact that Hannah is already dead, but you still want her to live after her trauma comes to light.
- Unlike in the book, the series shows us the subplot of Hannah's parents mourning over her death and how it affects them while they prepare for a lawsuit against the school and try to find out why she committed suicide.
- Throughout the show, Clay denies any romantic or platonic relationship to Hannah, choosing to say that they just worked together or the two of them had classes together when clearly, that wasn't the case. But after he gets to his tape and he finishes it, knowing how Hannah felt about him, he threatens to commit suicide by jumping off a cliff and is sent into a dream sequence where he refuses to leave Jessica's room after Hannah yells at him, begging her to let him in and finally telling her he loves her. He cries in Tony's arms, lamenting that he never got to hold her and tell her how he felt and that he killed her by listening to her and leaving her in that room alone.
- When Clay pours his heart out to Hannah, her response? "Why didn't you tell me this when I was alive?". Clay hugging Hannah as they both cry doesn't help as well...
- The worst part? Hannah says in his tape that he doesn't deserve to be on it due to the fact she calls him the nicest and kindest person she's met, but is included as he was there... and blames herself for pushing him away when she needed him.
Hannah: Clay... Helmet... you shouldn't be on this list...
- It becomes depressing when as Hannah and Clay are about to have sex, she has an Imagine Spot where she sees herself and Clay dating and being happy, all while holding hands with him and the school (including Justin, Jessica, Courtney, Zach, Alex, Tyler, Ryan, and even Bryce fucking Walker) all being happy for the two. Hannah even imagines Clay and her spending time with her mother as if she accepts Clay as Hannah's boyfriend. It goes into full-blown heartbreaking mode considering the What Could Have Been in-Universe had Hannah gotten together with Clay if she wasn't so broken at that point.
- Simply put, Clay's Tape boils down to Hannah basically telling Clay that he was the lone bright spot in her life and that she felt the same for him, but she, like him, just could not say so with how damaged she was.
- The biggest kick in the gut? Hannah firmly believes she would have ruined Clay's life had they gotten together. Clay's reaction is just as painful when he finds out why Hannah forced him to leave.
- Every single horrible thing Hannah undergoes, especially her rape by Bryce and Mr. Porter essentially telling her to move on from her rape if she refuses to disclose Bryce's name in her rape.
- Justin is portrayed as a Jerk Ass, but as time goes on and the story unfolds, detailing his abuse at the hands of his mother's boyfriend and her mother's parental neglect and how none of his "friends" are really there to support him, it's hard not to feel bad for him. There is also the fact that he is obviously both deeply ashamed of his failure to protect Jessica from being raped at the hands of Bryce as well as in deep denial about it.
- Jessica's downward spiral into recklessness and the PTSD that ensues when she remembers bits and pieces of being raped by Bryce while drunk, which Justin, after saying Hannah lied about it the entire show, confirms to be true. To find out your boyfriend allowed his best friend to rape you at your party, on your anniversary, almost verges into Nightmare Fuel territory.
- Clay discovering Skye's self-harm scars.
- Finding out that Jeff, the athlete that Clay tutored, the one who encouraged Clay to step out of his shell and to go after Hannah, was killed in an accident that was indirectly caused by Sheri, who was drunk and driving Hannah home.
- Tony disclosing to Clay that the reason he has Hannah's second set of tapes and the reason he's so adamant on everyone involved listening to the tapes is because she came to his house to drop off the tapes and he avoided her, due to the drama she had at school, only to go to her house and discover that she committed suicide, and the immense guilt that came from ignoring her when he did drove him to fulfill her wishes, as she trusted him to do so.
- Tony, telling his boyfriend in a shaken, lost voice everything involving his role in Hannah's tape circulation and the guilt he feels from keeping it all a secret from her parents, who trust and confide in him to help them discover why she would commit suicide.
- The infamous scene where Hannah graphically slits her wrists with a razor blade and bleeds to death in her bathtub and being discovered by her parents, shortly afterwards. All while being narrated by Clay to Mr. Porter. No poetic music, no artsy camera shots. Just a very despondent 17-year-old girl, hurting herself, with her cries of pain and her last shaky breaths before she silently passes away, alone, depressed, and crying.
- The lead-up to her parents finding her is... Heartbreaking. You hear Mrs. Baker, asking Hannah about the water leaking from under the door and jokingly commenting about it, but when she opens the door, her face just... drops. There's no scream or terror at first: Just her quietly processing what happened with small no's as she carefully approaches the tub and tries to pull Hannah out, all while telling her she's going to be okay before crying out for her husband and still telling Hannah's lifeless body that she's okaynote . Mr. Baker's reaction is worse, as he just tries to grab his daughter and just gets told by Mrs. Baker to go call an ambulance. Just... every parent's fear of finding their children dead.
- Hannah briefly running into the man who encouraged her to come to poetry group just before she commits suicide, who tells her they miss her and encourages her to come back, showing there are people who still care about her, but she's too far past the Despair Event Horizon to realise it.
- The build-up to her suicide is heartbreakingly scored with Ultravox's "Vienna", almost in a pre-emptive Really Dead Montage.
- When Clay confronts Mr. Porter, the Mr. Porter we see throughout the series slowly dissolves into a man who brokenly attempts to convince himself and Clay that he did everything he could, only to tearfully stop after Clay tells him in detail that after refusing to help Hannah, Hannah would wait outside his office in hopes that he would come after her, and when he didn't, after leaving the school and putting certain things in order, she would go home to commit suicide.
- Finding out that Alex shot himself in the head and is in critical condition by the end of the series.
- Tyler isn't exactly a clean individual, having stalked Hannah repeatedly and ruining her friendship with Courtney by inadvertently outing her and releasing a photo of the two girls kissing out of revenge for Hannah refusing his friendship, but he has zero issues with being outed for what he did to Hannah, claiming that he "loved" her, and then the reveal that he plans on shooting up the school as retribution for being bullied, judging by the small arsenal of pistols, a rifle, and a shotgun he has hidden in one of his photography cases...
- Hannah's poem from episode 8, especially the last four lines:
It must be possible to swim in the ocean of the one you love without drowning.It must be possible to swim without becoming water yourself.
- Of course, the kids at school all dramatically miss the point and focus on the first line, that mentions her Black Bra and Panties.
- Then Clay, not knowing who wrote the poem, calls them a "dark human being" and says, while he likes the poem, he's not sure he'd like to hang out with its author, unwittingly hurting Hannah even more.
- Zach telling Clay that he never threw away Hannah's letter and even still has it in his wallet. While Clay's reaction and his refusal to read Hannah's letter is bad enough, that one part where Zach stares at the note and even his lip quivers shows such...such regret.
Hannah: WHY ZACH?! WHY?!
- Even worse is the flashback: After Hannah drops her note to Zach, deducing that he's lonely like she (and by some extent, majority of the school) is, she watches Zach go through the small rack-bag and pull out the note and begins to read it out of the class. When she slowly follows him, she 'sees' him ripping the note. Hannah's reaction well...it's like everything else that she's endured.
- The worst part is as mentioned above, Zach never ripped up her note, implying either Hannah firmly believed Zach to be like all the douche jocks at the school or she's so broken at this point that she thought she saw that.
- In "Tape 2, Side A", Hannah describes how she'd go to a certain liquor store where she "felt safe", only to have that "safe" location ruined by Bryce Walker, who tries to play off as a nice guy and even pays for Hannah's items, only for him to grab her ass and smugly tell her she does have a good ass. What makes the scene unbearable is that as Clay listens to Hannah describe how defeated she felt about the incident and imagines her running out of the liquor store, in tears, and he tries to approach and comfort her when she's not there. GOD.
- The show also (but subtly) utilized social media (mainly Instagram) to go along with fans in the show's lore. Hannah's instagram is overly heartbreaking, especially a Instagram story where the aftermath of "Tape 1, Side B" is shown, where Jessica burns bridges with Hannah over Alex putting her name on the "hot list". Just seeing Hannah trying to tell Jessica the list is a lie only for her to block her on her own Instagram account and on Facetime is heartbreaking. Katherine Langford's heartbroken expression as she attempts to Facetime Jessica only to be told she can't Facetime her is hope-shattering..
- It's small but one of Tyler's targets for his planned school shooting is revealed to be Clay.
- Seeing Clay getting beaten up by Bryce after confronting him about his rapes of Jessica and Hannah.