[[caption-width-right:320:[[KissingCousins Poor girl just wanted some love]].]]

[[folder: Season 1/Volumes 1-4]]
* "Red-Nosed Reindeer", one of the sidestories and episode three.
** [[spoiler: After Kirito joins the Black Cats of the Full Moon, they all get annihilated, including Sachi, a girl who reminds him of his sister, and someone he swore to protect. He goes through plenty of shit to find an ultra-rare item that's supposed to resurrect dead players, and eventually gets it with the help of Klein and Furinkazan, only to learn it only works for up to ten seconds after death, the amount of time it takes once their avatar shatters for the [=NerveGear=] to destroy their brain. By that point, Sachi has been dead for six months.]]
** [[spoiler:Sachi hums the song while Kirito utterly breaks into ManlyTears]]. Bonus points for the darkly sad and lonely atmosphere of that inn room during Christmas Eve. [[spoiler:Sachi was his first love, ''especially'' in the web novels, [[SheIsNotMyGirlfriend regardless of what he says about that]]. Dude watched his first girlfriend die in front of him, just a few seconds before he reached her position.]] And the only reason his guildmates thought they could take on the challenge was due to Kirito lying about his own level, so they overestimated their own abilities. [[spoiler: While they were not in a relationship, the word choices he used (in the original Japanese, at least) strongly implies he was in love with Sachi. But he recognized that emotionally above love, they were first and foremost {{Living Emotional Crutch}}es for each other. Like two {{Broken Bird}}s hanging onto each other for comfort. Which makes her death and his subsequent breakdown even more tragic.]]
** [[spoiler:In episode 9, after taking the Gleam Eyes down, the moment Kirito wakes up the viewer can briefly see Sachi's face but with Asuna's voice. At that moment you suddenly start to realize Kirito has begun seeing parallels in the two girls, and likely he's begun to have feelings for Asuna, but he's likely constantly reminded of Sachi and her death that he's too scared to get close to her.]]
** Kirito does not expect to survive the quest for the ultra-rare item [[spoiler: that will resurrect Sachi]]. [[DeathSeeker He thinks he deserves to die in the attempt]] [[MyGreatestFailure for such a failure]]. If Klein's offers of help sound like he's trying to talk someone out of jumping off a ledge, ''that's because he is''.
* When Asuna hears Kirito's story in Episode 10 about [[spoiler:the death of the Moonlit Black Cats, the only player name Kirito mentions is Sachi's. When you remember Asuna's tearful breakdown later in the episode, you realize she said it because after hearing her name... she likely realized Kirito stayed a solo player not just because of their deaths... but because he couldn't save his first love.]]
* Pina's death is heartbreaking, especially to pet owners.
** It can also be seen as a tearjerking moment when the Drunk Apes are killed, especially to anyone who has ever worked with gorillas.
* Episode 12. That is all. [[spoiler:Yui's reveal and DisneyDeath. She comes back in ALO but still.]]
** Also serves for plenty of in-universe example. Just when [[spoiler: Kirito and Asuna were starting to feel like a real family. Asuna crying in sadness only amplifies this.]]
* Episode 13: Just as Kirito tells Asuna to stay back at the guild headquarters, [[spoiler: she refuses, telling him she'd kill herself if Kirito were to die. After he admits that he'd rather run away with her just so they'd continue to live with each other, she reminds him that their real bodies don't have much time left. She then begins to cry in his arms, saying that she wants to live together with him in the real world.]]
** HarsherInHindsight [[spoiler: in the next episode, where they both die]].
* In Episode 14, [[spoiler:Asuna dies in Kirito's arms after taking a strike meant for him]]. He picks up the fallen sword, surely ready to start a RoaringRampageOfRevenge and swings weakly at his opponent. No strength, no speed, no technique. His opponent barely even has to dodge. [[DespairEventHorizon He is clearly completely broken.]] [[spoiler: And then Heathcliff runs him through, the look on his face obvious that this is nothing more than [[MercyKill putting the poor boy out of his misery]].]]
** Before then, Kirito and his friends manage to fell a powerful boss. With fourteen high-level players dying in the battle, however, everyone's morale begins to break: with the bosses that follow being harder still, everyone begins to wonder if they really can win and escape from the game...
* The second half of Episode 15. [[spoiler: Kirito learns that Sugou is planning to make Asuna his and tells the boy never to see her again.]] He is completely in tears in the subsequent scene, crying against Suguha's shoulders. Later we see Suguha lie beside him as he sleeps, shedding tears as well, but for a [[AllLoveIsUnrequited rather]] [[KissingCousins different]] reason.
* [[spoiler:Episode 21. Kirito introduces his sister to Asuna, and, roughly at the same time, Asuna was near logging out. Had she not been caught, they would've finally been reunited.]]
* The hits keep coming in episode 22. First, there's Kirito's attempt at the World Tree's Grand Quest, the last obstacle before he can be reunited with Asuna. He ends up dying in the attempt. Leafa then puts herself in harm's way to retrieve Kirito's Remain Light and revive him. When he tries to re-start the quest, she begs him to return to the funny, friendly Spriggan she met, and pretty much confesses her feelings for him. Unfortunately, Kirito can't accept them, and is determined to save Asuna. [[spoiler:His uttering Asuna's name then causes Leafa to realize something frightening: after Suguha decided to bury her affections for her brother Kazuto, she decided to pursue Kirito...but if Kirito is trying to reach Asuna, that means that ''Kirito is Kazuto''! She has it out with Kazuto in the real world immediately afterwards.]]
* Episode 22 has Leafa guessing who Kirito really is. [[spoiler: Leafa/Suguha was preparing to forget her love for Kazuto by trying to love Kirito. She entered a brief HeroicBSOD when she finds out Kirito=Kazuto.]]
** Kirito's first attempt to charge the barrier over the World Tree is heartbreaking. Even as he bounces off of it, he just repeatedly throws himself at it, showing just how desperate he is to reach the woman he loves. Not to mention the sight of Yui pounding her hands on the barrier, frantically calling out for her mother.
--->'''Leafa:''' [''struggling to stop him''] Stop it Kirito, it's impossible! You can't get any higher from here-!\\
'''Kirito:''' [''cutting her off, nearly in tears''] ''I have to!'' ''Damn it, I have to try!''\\
'''Yui:''' [''desperate''] Mama! I'm here, mama! [''breaking into tears herself''] ''Mama!!!''
** His initial solo fight against the Guardians is both this and awesome. He's pushing with everything he has, more aggression than he showed even in his fight against Heathcliff, as memories of Asuna flash through his mind. With every one he sees, the more aggressive he gets. He wants to see his wife terribly and it shows.
** Speaking of the episode, Suguha only tells him to leave her alone in the Japanese dub. If you look at the English dub:
--->'''Suguha/Leafa''': [[AnguishedDeclarationOfLove I love you]]. Leave me alone.
* The whole situation of [[spoiler: Sugou[=/=]Oberon sexually assaulting Asuna in front of Kirito]] in Episode 24 is NightmareFuel, but it's also pretty grim on another level. [[spoiler: Kirito is so close to saving Asuna, when suddenly, Oberon cuts the reunion short and spams his Game Master status, pinning Kirito on the ground with gravity-based magic, chaining Asuna, and then as Kirito tries to get up, Oberon impales Kirito with his own sword and then procedes to tear parts of Asuna's garments off, and then states that once he assaults her in in the virtual world, he'll do the same thing to Asuna in the real world, while she is in a coma, in her hospital bed, and Kirito would be unable to prevent it. After saying this he proceeds to [[LecherousLicking lick her]] and do all sorts of nasty things to her, while Asuna starts crying in despair. Heck, Kirito, in his NearDeathExperience basically sheds a tear and completely gives up (in his words "facing reality"). If it hadn't been for [[EveryoneHasStandards Kayaba's]] spirit showing up and lending Kirito his system administrator status and giving him a HeroicSecondWind, [[TheBadGuyWins Sugou would've gotten away with everything]]!]] And this would've resulted in a DownerEnding.

[[folder: Season 2/Volumes 5-7]]
* [[IronWoobie Shino Asada]]'s backstory, in addition to being [[NightmareFuel disturbing]]: as a child, she had the misfortune of being at the post office when a crazed gunman held it up. She managed to take the gun away from the robber when he threatened her mother and shot him repeatedly. Ever since then, [[TraumaButton she can't look at guns, or even have someone point their finger at her like a gun, without suffering a nervous breakdown.]]
** Speaking of which, the ending for the GGO arc (Startear) seems quite beautiful, but the lyrics fit Shino's state of mind during this arc so well that it's quite heartbreaking.
* When Kirito runs into Death Gun [[spoiler: and learns that he is from Laughing Coffin from SAO]], he's so shaken, that when Sinon comes to check on him, he grabs her hand as she's about to leave, as if pleading her not to leave him. This continues on until his match with her where he's lost the will to fight and nearly throws the match.
* Near the climax, when Kirito insists that he wants to protect Sinon, she finally breaks down into tears of anger and despair, asking him if he's willing to protect a ''murderer''. It's even more heartbreaking seeing the vision of her 11-year-old self surrounded by other kids pointing at her and ''outright'' calling her a murderer.
* The ending for the Mother's Rosario arc in the anime. The song is beautiful yet sad and the scenes it play through feature Asuna and Yuuki hanging out together. [[spoiler: It's implied that Asuna is reminiscing about Yuuki after her death.]] [[WhatHappenedToTheMouse You don't even find out whether]] [[spoiler:any of Merida's guildmates survived SAO]].
* The side story, [[http://swordartonline.wikia.com/wiki/Sisters%27_Prayer Sister's Prayer]], essentially a prequel to Mother's Rosario. Not only does it drive home how hard life can be for Yuuki, [[PosthumousCharacter Ran and their new friend Merida]], but there's also the ForegoneConclusion about how [[spoiler:all three girls succumb to their illnesses in a year or two, and Ran died sooner because she insisted that Yuuki test the Medicuboid, which allowed her to get a clean room.]]
* In Volume 7/the Mother's Rosario arc, the name for the guild "Sleeping Knights" doesn't mean much at first. But then you realize that [[spoiler: most of them have a terminal illness, and their name is ''[[MeaningfulName Sleeping]]'' Knights.]] Needless to say, it's heartbreaking.
* Volume 7. All of it, both good ([[spoiler:Asuna's reconciliation with her mother, Kirito's BigDamnHeroes YouShallNotPass, every damn heartwarming moment between Asuna and Yuuki]]) and heartbreaking.
** Special mention has to go out to the end of the novel. [[spoiler:Yuuki is finally succumbing to her lifelong battle against AIDS, and Asuna convinces the Doctor to let Yuuki log into the Medicube one last time before the end. They meet at the same spot where the originally met, and Yuuki gives Asuna Mother's Rosario, her one of a kind 11 hit combo. Following this the Sleeping Knights guild show up and pay their last respects, and Kirito & Co. do the same. Finally, over a thousand players from the game put aside any conflicts and come to say goodbye to the Absolute Sword (or Zekken in Japanese), who fades away after thanking Asuna for all she did and saying "I tried my best to live... Here, I really lived...". And to top it all off at her RealLife funeral over 200 players arrive in the flesh, surprising everyone at the hospital who thought she had no friends.]]
*** It's even more heart-rending in the anime. [[spoiler:The episode even drops the normal titles, just to make sure that the focus of the episode is this one event, the final minutes of the greatest fighter in the entire game.]]
** The ED song for the ''Mother's Rosario'' arc episodes "Shirushi", which [[spoiler:is clearly sung from Yuuki Konno's perspective]], and the final lyric hits it home.
--> [[spoiler:I won't forget that I lived with you on this day]]

[[folder: Volume 8 and beyond]]
* The Alicization Arc, which has [[spoiler: Eugeo dying, Cardinal dying, Charlotte dying, [[AnyoneCanDie all within a few dozen pages from one another]]. Eugeo's death {{break|the cutie}}s Kirito, who [[HeroicBSOD blames himself]].]]
** [[spoiler: The attack on Ocean Turtle ends with Kirito's brain damage [[GameBreakingInjury getting worse]] to the point where he's out of commission for the next three books, even though he's still inside UW. The cover of ''Alicization Invading'' portrays the sadness quite nicely.]]
** [[spoiler: Made even worse near the end of ''Alicization Awakening'' when [=PoH=] [[KickThemWhileTheyAreDown beats him up while still suffering]] from his GameBreakingInjury.]]
** [[spoiler: Vassago isn't just kicking our hero while he is down, he's doing it [[ForcedToWatch in front of]] [[TrueCompanions Asuna, Lisbeth, Silica, Agil and Klein]], all of them made virtual prisoners of war by the brigand of Chinese and Korean players, and they can only watch in horror as their friend gets beaten like a ragdoll. [[ShellShockedVeteran Lis' reaction even feels like someone experiencing PTSD from fighting a war]].]]
---> [[spoiler:'''Lisbeth''': "Everyone... I did this... to... everyone..."\\
'''Asuna''': "No... No, Lis! Itís not your fault, Lis. It was me... if only I could have thought this out more, if only I could have predicted this..."\\
'''Lisbeth''': "Asuna... I... didnít know anything. [[WarIsHell How horrifying war is]]... how painful it is to lose... I didnít know anything..."]]
* ''Alicization Lasting'', while not as bad as the previous three books, has plenty of these:
** [[spoiler:Kirito's JourneyToTheCenterOfTheMind moment is a mix of this, and NightmareFuel. Seeing his past memories and Eugeo's dead body [[HeroicBSOD takes a huge toll]] on the poor kid to the point that ''[[DrivenToSuicide he would've killed himself]] [[BeatStillMyHeart by crushing his heart with his bare hands]]''... if it weren't for the images of Asuna, Leafa, Sinon, and Eugeo [[YouAreNotAlone snapping him out of it]].]]
** [[spoiler: And after ending the war in UW, he still keeps Eugeo's sword as his TragicKeepsake. Kirito's bond with Eugeo is [[LivingEmotionalCrutch just as important as his relationship with Asuna]].]]
** [[spoiler: The fact that Kirito is stuck in UW for 200 years is very heartbreaking, especially when he weeps at the World End Altar while thinking that he won't be able to see everyone in the RW again. Fortunately, he's not the only one: Asuna stays behind UW to be with him.]]
** [[spoiler:Alice's speech at Project Alicization's launch day. Also doubles as a heartwarming moment:]]
--->[[spoiler:'''Alice''': I have met with people of the real world many times. In this strange world where I'm all alone, they encouraged me, cheered me up. They taught me many things, showed me to lots of places. I like them. But that's not all...... There is only one person in this world, I love him. Now that I think I might not be able to see him again anymore...... this mechanical chest feels like splitting apart...]]
** [[spoiler: After being transferred back to the hospital from Ocean Turtle, Asuna pays Kazuto a visit and placed a new blue rose in his bedside table. Said rose brings him sad memories in UW: their friends in said server have passed away of old age.]]
** [[spoiler: The first thing Kazuto did after going back home from the hospital is [[TheMourningAfter mourning Eugeo's loss]]. It hits him '''''[[BreakTheCutie so bad]]''''', even Suguha has to listen to his story in UW after comforting him.]]

[[folder: Video Games]]
* ''Hollow Fragment''
** When Strea [[spoiler:finally reveals she's an MHCP, and states why she tried to stop Kirito and the others from clearing the game, only to feel conflicted about trapping her friends... it makes the fact she's dying of a poison no one can cure all the more heavy. It's even worse when she [[AndIMustScream fuses with the Hollow Avatar against her will and is essentially a prisoner]].]]
* ''Lost Song''
** Rain's reason for trying to get into Shamrock becomes this when it's revealed that [[spoiler:Seven's her little sister, and she doesn't even know because their parents divorced when Seven was still young.]]
* ''Hollow Realization''
** There was a quest chain involving Yui finding and befriending a puppy called Mr. Woofles. They help her get back to the forest and have a heartfelt farewell. However the quest hasn't ended and it's revealed Mr. Woofles is in danger from Kobold attacks. Kirito, Argo, and Yui return to the forest and fight off a lot of Kobold mobs, however some of them sneak up to attack Yui. Mr. Woofles (now adult sized) jumps in to rescue Yui and saves her. However it's revealed she had been injured prior to showing up. A despaired Yui watches as Mr. Woofles succumbs to her wounds and passes away. Soon after, the heroes find five puppies that look just like Mr. Woofles, which turn out to be her litter. Mr. Woofles had been protecting her young ones from the Kobold attacks, so Yui and the others swear to take care of them just as their mother had done so.
** When Ritcher reveals to Kirito that [[spoiler:Sinon killed someone, the cutscene image that follows shows Sinon giving a horrified look as the sky above suddenly becomes all cloudy and dark. It fully reflects Sinon's mood at that moment.]]
* ''Accel World Vs Sword Art Online: Millennium Twilight''
** It's revealed that Persona Vabel is really [[spoiler:Yui from 1000 years in the future, who has become despaired due to both her parents having died of natural causes while she herself is left alone. Her programming prevents her from ending her own life, so she resorts to traveling back in time to take her younger self and prevent her from every existing in the first place so she doesn't have to live with the pain]]. The scene where [[spoiler:Kirito and Asuna find out the truth and try to talk Vabel out of it is truly heartbreaking. The scene ends with Kirito and Asuna tightly embracing Vabel as all of them cry]].

[[folder: Ordinal Scale]]
* [[spoiler:The whole part where Asuna learns she's becoming amnesiac. First the nightmare she has about Kirito forgetting her, then when she wakes up, she tries to recall her memories with him in SAO, but their faces are blurred out. And she breaks down while trying to make tea after learning that more of her memories will be lost. Sure, she gets better by the end of the film, but still...]]
** [[spoiler: In one specific moment, Asuna is comforted by Kirito, who says she's simply temporarily losing her memories of SAO. A shocked expression rises up on Asuna's face. Then she lowers her face with her bangs covering her eyes as she mimes the command that summons the SAO menu repeatedly much to Kazuto's concern, places her hand upon her wrist while shaking and quivering as she approaches tears. Then she faints deathly-pale.]]
* In spite of [[spoiler: Yuna's AI Replica]] pleading with her father to [[spoiler: not deep-scan the brains of the Sword Art Online survivors trapped in the stadium and potentially murdering 3000 innocent people, the professor furiously snaps:]]
--> BE QUIET YUNA! I would gladly [[DealWithTheDevil sell my soul to The Devil]] if [[spoiler: I could bring you back! Even if... even if I must repeat what was done by the man who murdered you (Kayaba)... It is worth it if I can bring back those irreplaceable moments!]]
** And when the grief-maddened [[spoiler: professor collapses in despair as his schemes to bring back his little girl is thwarted by Kirito and his friends,]] Yuna's [[spoiler: spirit returns from heaven and]] warmly tells him.
--> [[spoiler: Thank you Daddy, and goodbye.... I will always be with you; in your memories.]]
** The above desperate quest to recapture a lost past only makes the ending theme of the film, ''Catch the Moment'', doubly meaningful and sad.
** [[spoiler:The backstories of Eiji and Yuna: both were trapped in ''SAO'', with Yuna having found her way into the game thanks to her father's connections in Argus. Eiji joined with [=KoB=], but was a rather weak and meek player who never really stood out. Then he met Yuna, who had become a bard in the game as an extension of her love of music, and the two became quite close. Sadly, Yuna died during a boss battle, dying in the real world as well. Eiji happily threw his lot in with Shigemura in the hopes that his plan would bring her back to life as an artificial intelligence.]]
** [[spoiler: On top of that, imagine how Eiji felt when he was betrayed by Shigemura. Eiji wanted Yuna back as well. But Shigemura needed Eiji's memories of Yuna, especially since he was the closest to her in SAO. The next thing Eiji gets is a chewing out by Shigemura for failing him, then summoning a high level boss to finish him off to extract Eiji's memory.]]
* [[spoiler: The unexpected twelfth hit of Asuna's Mother's Rosario... Yuuki may have been smiling, but it's hard not to tear up.]]
* Yuna got to fulfill her dream of performing live at a concert. The song she sings is "[[https://www.youtube.com/watch?v=SRiLZKCChbI Smile For You]]" with the lyrics being extremely saddening and tearful. Once this is done she is okay with dying, having finally accomplished her goal in life.