Say you have two characters. They may mean the world to each other or they may argue a lot but still have begrudging respect for the other. Then, something happens that causes a rift between them of a Et Tu, Brute? sort. Only that's most likely not their fault or rather they didn't intend for it to be perceived as a betrayal. This could also occur between two characters that are not close but still know each other.
This sometimes involves a character making a drastic decision with noble intentions possibly to help their loved ones, strengthen their friendship with that one character, help the other out etc.
Sometimes the assumed betrayal is a prime target for a villain to use to their advantage and compel the one who thinks they were wronged into joining their side and to help them get what they want, be it revenge for the perceived betrayal, etc. Of course, a villain could also have a grudge against the hero, and uses this trope as a deliberate ploy to make them look bad to their loved ones by framing them.
Things may go From Bad to Worse for the other character and because of that they perceive their former friend to blame all because of actions they took that they thought would be beneficial in some fashion or perhaps it was not an action taken by choice.
Sometimes this can also happen when a character may be going through a stressful time so they take it out on other characters. They may spread lies and cause drama purely to make themselves feel better and instigate a perceived betrayal between themselves and someone else or between other characters.
A downplayed example could involve a character using another character for their own ends, but they end up Becoming the Mask and genuinely grow to care for them. Therefore, when the other ends up discovering the initial truth they hid behind the mask, they are quick to feel betrayed, much to the mask becoming character's dismay. At that point, the betrayal was no longer intended on their end, hence their becoming the mask.
Can also occur in a Not What It Looks Like situation.
Seems similar to Third-Act Misunderstanding, but set up as an inciting incident for a larger plot rather than a device to resolve the existing plot.
Supertrope of Mistaken for Cheating. See also Stab the Scorpion. May tend to occur due to Poor Communication Kills. Can sometimes come off as some manner of Disproportionate Retribution to the party (as well as the audience) receiving the retribution for the perceived betrayal.
- Berserk: Guts and Griffith are close when in the Band of the Hawks together. They are content working towards Griffith's dream until Griffith declares in a speech to Charlotte while unaware that Guts is in earshot that a true friend/his equal would pursue a dream independent to his own. From this, Guts makes the decision to leave the Hawks so he can truly be called Griffith's friend. Griffith basically takes this as an affront to himself, not as a genuine act by Guts to strengthen their friendship, and they duel with Griffith losing. Depressed, he sleeps with the princess and ends up getting put to a year long torture for it. He blames Guts for this in a roundabout way, and then Guts and co. rescue him. He hates Guts for what he thinks is his fault and further falls to pieces when he sees Guts and Casca have become an item and they talk about leaving the crippled Griffith behind. They were both only trying to make a life for themselves and what ended up happening to their relationship with Griffith was the last thing Guts or Casca wanted. Things get worse for the two when Griffith becomes a Godhand member and makes them pay during the Eclipse for everything, all started by a perceived betrayal.
- Code Geass: Many characters in the series are known for this, with Suzaku and Lelouch being the ones it happens to most often, although sometimes it is not entirely without reason. Indeed, Lelouch tends to fall into being a perpretrator of many percieved betrayals to others though he really is a Well-Intentioned Extremist who wants to make the world a better place for his beloved sister Nunnally. He utilizes this to fulfill his goals as he wants to commit Suicide for Others' Happiness by making himself out to be the most hated and evil ruler that needs killing off to make the world a better place.
- Fushigi Yuugi: Fuels much of the drama between best friends Miaka and Yui. Yui tends to see the world in black and white terms and is easily infuriated with perceived betrayal. Thus, when she tries to help Miaka and suffers for this Nakago is able to corrupt/manipulate her into believing its Miaka's fault, thus fueling much of the plot and her vendetta against her.
- Hetalia: Axis Powers: Played as dark comedy when America is aware of this trope and uses it to force England to come back to his senses when the latter is laid up with a bad cold. England thinks he's dying and gives a Death Bed Confession to America about how he feels about him. Suddenly, the grim reaper puts his hand on England's mouth and he "dies". America quickly says "Yay, finally!" which causes England to wake up and gives him the impression that America wanted him to die. America smirks and says to the grim reaper he knew that that would wake him up. Basically, America assumed a facade to make England think he was betraying him and wanted him dead all to make him wake up from his illness.
- Neon Genesis Evangelion: One of Asukas sore points is that Shinji always saves the day before her; when she's undergoing the Trope Namer of Mind Rape, Gendo forbids Shinji from going out and saving her. Later on, Rei gets into a pinch and with Asuka unable to pilot, Shinji is scrambled to assist but fails. Cue Asuka believing that Shinji let her suffer on purpose. Then comes End of Evangelion and she releases all her pent-up rage against the MP Evas, to spectacular effect — right before suffering one of the most Cruel And Unusual Deaths in the entire franchise.
- The confrontation between Shinji and Asuka that triggers Third Impact also falls under this. Shinji begs Asuka to help him in his moment of crisis, but due to his perceived betrayals she first attacks and ultimately rejects him. This causes him to flip out because he takes it as a betrayal.
- Peacemaker Kurogane: During an attack on the heroes in the end of the first series, Tetsu tries to hold off Yoshida, who means to kill him and his friends and cuts off his arm. Yoshida gets the drop on Tetsu before Okita retaliates by cutting off his head from behind, killing him. Unfortunately, his charge Suzu arrives in the instant Tetsu shields his sword by the remains and comes to the assumption (since Tetsu is the only one in the area) that Tetsu, who is his only friend, has killed his beloved master. He Goes Mad from the Revelation and swears vengeance on Tetsu. Though there are other contributing factors (including being abandoned and nearly dying from starvation) as well.
- Peach Girl: Used as a way to further the plot among the main cast, usually to fuel relationship drama, mostly among Sai and Momo. Although they eventually make things work out between them.
- Reborn! (2004): Enma becomes friends with Tsuna who has to rain check on hanging out with him once due to Vongola duties. He leaves him a note explaining everything which ends up lost before Enma can read it. Therefore, Enma believes Tsuna declined to meet him without giving a reason and feels resentment. Also not helped by how his ancestor of his family gang was seemingly betrayed by the ancestor of the Vongola family. Daemon Spade uses this to his advantage to brainwash Enma into attacking Tsuna with intent to kill. In Chapter 331 Tsuna puts a lot of effort into trying to save Enma who had gone past the Despair Event Horizon and couldn't hear anyone through all his rage and despair. Tsuna calls Enma (I'm your friend remember!?) and Enma finally comes to his senses remembering the moments they spent together in the past. They have a heartwarming moment together where Tsuna tells Enma while smiling warmly "It's okay now...I came to save you..." and Enma responds with "Tsuna-kun...Just like the Vongola Primo...You didn't betray me..." while also smiling warmly.
- Things go to hell in a hand basket for the Quinx in Tokyo Ghoul re as soon as their leader and mentor Kaneki/Sasaki defects from them; for Mutsuki in particular. Mutsuki was codependent on his mentor and loved him even, so when Kaneki left and supposedly killed Arima, the revered figure of the CCG, Mutsuki went insane. This also occurred because of Mutsuki being captured and tortured by his stalker Torso and his horrendous backstory. He assumed his mentor's defection was meant to be a betrayal when he sees him in the hideout of their enemy (Ghouls) with a ghoul woman he comes to love, as well as assuming he killed Arima. The reality is Kaneki knew he had to fight Arima again and knew he might end up dying to give his friends chance to escape from him; during his mission to save Hinami, a ghoul little sister figure which is partially why he defected in the first place. Kaneki ultimately refuses to kill Arima who ends up committing suicide because his time was coming from a deathly illness. Kaneki decided to take the rap, lying that he killed Arima. The CCG and Mutsuki believed him of course. Luckily, it all works out.
- In a flashback on Yu-Gi-Oh! 5Ds, Team Satisfaction leader Kyosuke Kiryu is wanted by Sector Security for attacking an officer. Yusei Fudo tries to take responsibility for the attack and turn himself in, but Security arrests Kiryu anyway. When Kiryu sees Yusei with Sector Security, he assumes that Yusei turned him in and vows revenge.
- In the manga Yuri is My Job!, two girls, Mitsuki and Hime, were once good friends in elementary school, having played piano together a lot. But when Hime hears that some girls are spreading rumors about Mitsuki bullying her into performing in a recital, Hime quits in order to protect Mitsuki's reputation. But she doesn't tell Mitsuki about it, who winds up hearing about it from the music teacher. At one point, Mitsuki overhears Hime talking to some girls and concluding that Hime's decision was a deliberate betrayal. As a result, their friendship is broken for several years, and when they reunite in high school, Mitsuki makes it very clear that she DOES NOT like Hime at every opportunity. Thankfully, halfway through volume 2, the girls manage to make up and resolve things.
- Robin (1993): Damian sneaks into the batcave and claims to need his father's help to protect him from Ra's. Since Bruce isn't home and Damian is talking to Tim, who he tried to kill with a grenade during their last meeting and who knows Ra's recently died, Tim thinks Damian is trying to kill or impair Batman. Damian does not help his case when his reaction to Tim's skepticism is to shoot a grapple gun at Tim, and run into the manor. Tim thinks he's going to kill Alfred and is entirely unwilling to listen after this.
- The Night Unfurls: In the remastered version, upon seeing Olga accompanying Kyril on the road to the capital, Grace feels betrayed by how Kyril insists on protecting the woman she hates in order to complete his mission. To be fair, he had no idea about the animosity between the two.
- In RWBY: Scars, Blake runs away after the White Fang attack Beacon without telling her team. She was running from her abusive ex-boyfriend Adam and didn't want her loved ones to get hurt. Everyone initially thinks she died and her body was just never found, however Velvet brings Yang back Blake's sword and helps her realize that Blake is alive. Yang, however, comes to the conclusion that Blake was an inside agent for the White Fang the entire time and she betrayed her "friends".
- Anastasia: Dimitri is a con man after the reward money for whoever returns Anastasia to her grandmother the Empress. He finds a orphan girl Anya has a astounding resemblance to Anastasia and convinces her she might be her but does not tell her about the reward money. Dimitri ends up genuinely falling for Anya (and realises she really is the missing princess to boot) but realizes this too late. When he tries to convince the Empress he has Anastasia with him she is so distraught from feeling like she was being played by so many people for her money, when all she wanted was to find her last remaining family member. She had said her heart cannot take it anymore and has Dimitri dismissed. Anya hears the whole thing and believes Dimitri was also using her. However, he has grown to love her and genuinely wants to reunite her with the Empress, and the money does not matter anymore. She does not listen of course and they almost go their separate ways but they reunite and do the Dance of Romance at the end, after saving the other from Rasputin.
- In Frozen, Anna was accidentally hit by Elsa's ice powers when they were playing together as children so a group of Trolls wipe and replace her memories of the event. As a result of this, their parents decides to have both Elsa and Anna locked away in their palace home with the former also shutting her out for thirteen years as she struggles to control her powers. While they did it to keep Anna safe, since her memories had been changed by the Trolls she does not know the real reason for all this and assumes Elsa has it in for her, owing to her cold nature. It also does not help that 13 years later, when trying to persuade Elsa to bring back summer after she unleashed an Endless Winter upon the kingdom, she made Elsa snap and accidentally struck her sister in the heart when the former is losing control of her powers due to emotional stress but since she neither knows her sister's distress nor the look of remorse upon realizing it, she assumes that Elsa did in on purpose with Anna having such a look of betrayal on her face and deeply saddened, ultimately gives up on her sister, admitting to her fiancee Hans that she was wrong about Elsa when trying to thaw out her frozen heart by an Act of True Love
- The Little Mermaid II: Return to the Sea: Ariel, who was once a mermaid herself, and has married a human, Prince Eric, longs to introduce her baby daughter Melody to the sea. However, because of Ariel's ties and history with the ocean, Melody is almost eaten as a baby by the henchman of Ariel's diseased nemesis's sister Morgana. Ariel feels responsible and horrified she almost lost her daughter so she orders Melody to have absolutely no contact with the sea to protect her, even having a wall built around the castle. However, Ariel's attempt to protect her ends up making Melody even more fascinated with the sea and it gets her into trouble with Morgana. Morgana turns Melody into a mermaid at her wish with the request that she get her Triton's trident to make the change more permanent. Being evil, she has no desire to help Melody and merely wants the trident to rule over land and sea. When Ariel turns back into a mermaid to try to find and help Melody she comes across the two and implores Melody give the trident to her. Morgana manipulates Melody, telling her she's given Melody everything she's ever wanted while Ariel was only lying to her about the sea being dangerous all these years. While Melody does end up giving the trident to Morgana and nearly dooming her family, she didn't think that Morgana actually had it out for them to start with, and her emotional hurt over her mother's misguided attempt to protect her made her act rashly.
- In Hussar Ballad, when Shura infiltrates the French camp in a French officer's guise, her uncle, taken prisoner and half-delirious, mistakes it for her actually betraying the Russian army. He starts pleading with her not to say anything, telling her not to be scared of interrogations, and revealing she is his niece. It leads to the death of the French lieutenant who has been covering for her and almost leads to Shura herself getting shot.
- In the film version of The Lord of the Rings: The Two Towers, Faramir threatens to kill Gollum for catching fish from a sacred pool, but Frodo convinces him to spare him and goes to the edge of the pool to try and talk Gollum into leaving the pool freely. Unfortunately, Faramir's rangers decide to use Frodo as a distraction to capture Gollum and torture him instead, leaving Gollum with the impression that Frodo betrayed him to the rangers. Poor Frodo is thoroughly aware of what it looks like and tries to minimize the damage, to no avail.
- In Ran, Hidetora divides his kingdom between his three sons; when his youngest son, Saburo, speaks out against this plan, warning Hidetora that they might turn against each other, Hidetora thinks that this warning is really a veiled threat and banishes Saburo. As it turns out, Saburo's warning was quite prescient, and it's not long before Hidetora's sons turn against each other and against Hidetora.
- In Pokémon Detective Pikachu the amnesiac titular Pokemon is shown a vision where he seemingly betrays his partner, Harry, in order to free Mewtwo (in reality, it was Harry who had ordered Pikachu to free him - Mewtwo was recaptured by one of the antagonists before this could be revealed, however). Interestingly for this trope, it's Pikachu himself who believes he's a traitor, while Tim, Harry's son, is convinced that there's another explanation.
- The killing of Dumbledore by Snape in Harry Potter and the Half-Blood Prince is initially taken as treason by the Order of Phoenix before Snape himself reveals, in a sort of Deathbed Confession, that it was part of a plan by Dumbledore himself.
- Vampire Academy: Rose has a soul bond with Lissa after the latter brought her back to life. They are close and Rose acts as her guardian in training. She is expected to work to keep her safe while she moves up as a Moroi vampire princess. Lissa uses compulsion magic sometimes to compel people into acting a certain way for her or doing things for her, which she sometimes uses to help Rose out. This is forbidden amongst Moroi and Christian (her love interest) disapproves. He is also known to have had parents who turned Strigoi (The Big Bad of this world) so people mistrust him along with his other behaviors (like setting fire to people with his magic who were ganging up on Lissa). Rose especially does not like or trust him and after a pretty emotional scene with some classmates prior, she takes it out on Christian. She lies to him that Lissa thinks he is a freak and does not like him. He takes it literally and avoids Lissa, who is hurt as to why he would avoid her, taking it as a betrayal and putting them at odds with each other. For what it's worth, Rose does see the error of her ways and helps them patch things up.
- After Lissa heals for the first time she steadily becomes crazy and depressed. Therefore, she doesn't take things well when she learns Rose deliberately hid horrific news about a teacher named Mrs. Karp from her. She did it to spare Lissa's feelings of course, but Lissa is hurt that she kept this from her and decides to stop hanging out with her for a time, which (seeing as Lissa is the school's idol) other classmates emulate and ignore her too.
- The King Loves: Happens twice in rapid succession. An assassin tries to kill the king with one of Won's arrows. The king assumes Won was trying to kill him. Rin, who saw what happened, decides to shoot at Won to prove he's also being targeted and so he can't be the assassin. Won didn't see the attack on his father, so from his perspective his best friend attacked him for no reason.
- Awkward.: After Jenna breaks up with Matty and starts dating Collin, things are understandably tense between her and her friends, who are trying not to take sides. Just before an attempted barbeque at Jenna's house, Tamara, Ming and Jake are getting ready, when Tamara and Jake get into a huge fight over Tamara not telling Jake about Jenna and Collin's affair. This causes Tamara and Ming to miss the barbeque. Jenna takes this as a betrayal, assuming they just didn't want to hang out with Collin, screaming at them over text, insulting them in a call and then deleting them on social media.
- In season 3 of Queen of the South Kelly Anne van Awken is tricked into believing that religious fanatic El Santo is targeting her boss, Teresa Mendoza, who is also his client. Eager to protect Teresa, Kelly Anne gives up information about El Santo's whereabouts to the CIA, who arrange a drone strike. Unfortunately, said drone strike occurs while Teresa has been summoned to El Santo's compound, causing her to nearly be killed. Naturally, when Teresa finds out that Kelly Anne has been talking to the CIA, she assumes that Kelly Anne betrayed her and orders her to be killed.
- The Barrier: When Luis commits an act that puts him at odds with the government and gets him branded a traitor by the President, Luis' wife Alma is assumed to be an accomplice. Alma was actually just as blindsided as the President when Luis committed the act.
- In The Shield, Shane is tricked into believing that Lem has made a deal to protect himself while selling out the Strike Team, so he reluctantly drops a grenade in Lem's lap. Upon finding out that he killed his friend for nothing, Shane became distraught and suicidal.
- In the Moonbrooke chapter of Dragon Quest Builders 2, the Builder is asked to build a dungeon, not knowing that the people of Moonbrooke are planning to lock up the Builder's best friend, Malroth, because they think that he is dangerous. The Builder repeatedly asks the king and soldiers when Malroth will be set free, and is finally allowed to release him right before they fight the world boss. However, Malroth takes this to mean that the Builder is only releasing him because he has become useful again, and refuses to let the Builder explain themself. Malroth's feeling of betrayal leads to Hargon kidnapping and controlling him.
- In Final Fantasy VI, Kefka ambushes the party at the Magitek Factory and claims that Celes (a former General in the Empire) was The Mole. Given her background, even her love interest suspect her; at least until she proves her loyalty by pulling a Heroic Sacrifice.
- In Kingdom Hearts, Sora is separated from his friends Riku and Kairi. He goes on a mission to find them and picks up some new friends along the way. Riku reunites with him and then Riku sees him with his new friends, and takes this the wrong way. Not helped by how he was with Maleficent at the time who is The Corrupter and subtly manipulated him into turning on Sora. Riku now believes Sora does not care about him or Kairi anymore and gives in to his darkness. He gets better.
- In Starcraft: Brood War, late in the UED Campaign, Vice-Admiral Alexei Stukov retreats out of the battle of Aiur without much explanation. Admiral Dugalle is dumbfounded as to why he'd keep secrets from him, his long-time friend. Newcomer Samir Duran suggests that Stukov is up to something, and it turns out that he's retreated to Braxis to re-activate the previously-assumed dismantled Psi-Disruptor, against Dugalle's orders. Dugalle immediately assumes the worst and mandates a capture order on Stukov. Upon confronting Stukov, Duran wastes no time in shooting him in cold blood. With Stukov's dying breath, he explains that Duran was the mole and managed to turn Dugalle against Stukov in an attempt to sabotage the Psi-Disruptor in order to compromise the UED's mission.
- During the "Spirit of Yarikawa" sidequest in Ghost of Tsushima, Jin is told that one of the survivors in a survivor camp, Heitaro, spends long periods of time away from the camp every night without telling anyone what he's doing, causing the other survivors to believe he's a Mongol spy. Heitaro informs Jin that what he's actually doing is mourning his deceased lover, Tojiro; the two were in a homosexual relationship, but Tojiro was married with children, who survived and are in the same camp. Heitaro feels he can't admit what he's doing without besmirching Tojiro's family's memories of him. Jin advises him to leave the camp, as someone had asked the "Spirit of Yarikawa" to kill him; Heitaro promptly does so.
- In the early seasons Weiss is suspicious of Blake due to her supposed ties to the faunus terrorist organization, the White Fang. It is not helped by how she keeps running off. Blake, however is so stressed out keeping her and her friends out of danger that she runs away from it all. This breeds mistrust among Weiss, and while she was never close to Blake by any means, she still is hurt by this. Especially so considering Weiss has a history of people connected to her being tormented and killed by the White Fang. Blake however, is far from being a antagonistic person; especially one who is worthy of being a member of the current White Fang.
- Yang grows close with Blake and thus is also hurt when Blake leaves. Blake left to figure things out and get stronger after trauma befalls the group in later seasons. Yang does not understand the true reason why she left. In her eyes, there was no good reason for her to leave as that was after she lost her arm to Adam and when she needed her most. Blake was not thinking in her blind distress of course, and did not intend for it to come off as her abandoning Yang and hurting her like she did. Luckily, the two patch things up and take on Adam together in a final standoff.
- Hey Arnold!: In Helga's Makeover, Helga is considered too unfeminine to be invited to Rhonda's all girl slumber party. That night when sneaking a peak of their party she catches them making fun of her bullying ways and unorthodox behaviors and threatens to beat them up. She then sees her one friend Phoebe, who she thought would defend her, end up laughing; though she did not mean anything by it of course considering how good-natured Phoebe is. Helga takes her laugh to mean she has turned against her and threatens to get them all back, by surprising them after a personal makeover to make herself look more womanly.
- Angelica is known for being a Spoiled Brat, so no one usually thinks she has selfless intentions. The one time Angelica tries to make something up to Suzie when the latter suspects her of some wrongdoing, Angelica is taken as being up to no good again. However, Angelica was sincerely sorry for breaking something on Suzie's bike, and made a craft picture to apologize. Suzie was so suspicious, she nearly had the other babies get rid of Cynthia, Angelica's beloved doll. This made Angelica feel betrayed, the whole mess coming up from miscommunication and Angelica's less-than-stellar track record.
- Tommy thought Chuckie was against him when he was upset his teddy bear was ruined and Chuckie said he could get a new one. Chuckie meant nothing by it.
- She-Ra and the Princesses of Power:
- In season one, Entrapta is seemingly caught in an explosion during a rescue mission to the Fright Zone and is presumed dead by her teammates. Entrapta actually escaped into an air vent, didn't realize they thought she was dead, and spent several days in hiding, waiting for them to come back for her. Catra discovers Entrapta, takes her prisoner, convinces Entrapta that her friends had deliberately abandoned her, and gets her to switch sides.
- In "Moment of Truth", Catra knocks out Entrapta and has her banished to Beast Island before she can tell Hordak the potential risks of activating the portal without further tests because she would rather destroy the universe than allow Adora to have another win against her. When Hordak asks where Entrapta is, Catra tells him that she was the one who let the Princesses infiltrate the Fright Zone in their rescue mission. Since Hordak has grown to like Entrapta because she accepted him for who he was and tried helping him upgrade his suit and his portal technology, he is especially hurt by the implication.
- Steven Universe: In "Message Received", Steven and the Gems think Peridot is planning to betray them after she salvages a communication device from the Moon Base. She does use the device to contact Yellow Diamond, but only to try to convince Yellow Diamond not to destroy the Earth.
- Totally Spies!: Somewhat happens to poor Clover when her friends walk out on her in favor or their new boyfriends. The truth is their respective boyfriends are actually the same person who was a villain using a cloaking device to take on the appearance of numerous guys. He gets girls to fall in love with him and dumps them. He was bitter from always being dumped by girls he fell in love with. Clover was trying to warn Sam and Alex but they were so entranced by this mans tricks that they almost ruined their friendship with her. Clover knew the truth of why they nearly did so of course but it still hurt. Even so she still decided to help everyone.
- Happens again to Clover with her friends when a vengeful villainess frames her for various things to make her look bad to them.
- The Transformers: The Season 2 episode "Traitor" focuses on Cliffjumper accusing Mirage of being a traitor to the Autobots based on flimsy circumstantial evidence. In the end, Mirage is able to prove his innocence and Cliffjumper apologizes to his friend for having doubted him.