The King of Midland in Berserk seems like a pretty mild, decent guy...until he discovers that Golden Boy Griffith slept with his daughter the previous night. So he has Griffith locked in the deepest level of the worst dungeon in Midland and put to the torture by the most sadistic little freak in the world, while also having Griffith's mercenary army, the Band of the Hawk, declared outlaw, butchered and hunted endlessly. Overreaction much?
It wasn't so much Griffith sleeping with Charlotte that set him off. It was Griffith correctly deducing that the King was lusting for his own daughter (in which case Griffith beat him to her virginity) that caused him to go, ah, berserk. The latter even prompted the King to give free reign to the torturer on how he went to work on Griffith, something even the torturer himself couldn't believe.
And then, after Guts returns and the Hawks regroup and rescue their former leader, the King decides to send in the Black Dog Knights, the worst rapists, murderers, and all-around scum Midland has to offer, led by a truly nasty piece of work of an Apostle, in order to kill them all.
In Bleach, Aizen pays more attention to his captive Orihime than to his biggest fangirls, Arrancar twins Lolly and Menoly. Their response? To get Orihime alone, and beat the shit out of her. When that fails (only on the fortunate timing of Grimmjow), their plan is to kill her while Ichigo is fighting Ulquiorra.
Another one would be Tousen. His closest friend was killed by her shinigami husband. So what does he want to do? Get rid of all the shinigami, all who have nothing to do with his friend's death.
The main reason for Tousen's revenge may have been that the Central 46 did not sentence to death the man that killed his best friend over something petty and so he wants to take down the entire Shinigami system through the most bloodless way possible: letting Aizen, a traitor, take over the throne to Soul Society.
Aiding Aizen's coup de tat was somehow "the most bloodless" action possible? Even though Aizen intend to slaughter a whole town in the living world and harvest their souls to materialize a key that would unlock God's domain, in which Aizen would kill said God and forcibly take over? Riiiiight. One can only imagine the route Tousen would consider "bloody" by comparison.
While it's often overlooked because of the character's popularity as The Rival, Grimmjow's rivalry with Ichigo is insanely petty and mean-spirited. They are introduced when Grimmjow beats the unholy hell out of Ichigo until he can barely stand upright (purely to show up Ulquiorra, who Grimmjow dislikes), and Ichigo manages to get in a single counter-attack bad enough to scar Grimmjow's chest superficially. This insignificant injury combined with the fact that Ichigo's self-confidence irritates him is all the justification Grimmjow needs to go from picking on Ichigo to show up Ulquiorra to crusading against him with a hatred that borders on obsession.
Captive Hearts: Because a thief tried to rob the Kougamis centuries ago, his descendants were forced to serve the Kougamis for the next hundred generations.
Change 123 has Sora — who is using Kosukegawa to get Motoko mad so she can see her most powerful personality, Zero — chuck into a dumpster some Kamen Raider tapes that Kosukegawa gives her, tapes that are very important to him. Hibiki (the most abrasive of Motoko's normal personalities, all of who like Kosukegawa) sees this happen. Her response? Throwing a punch that makes Sora's bone stab out of her wrist. Ouch.
Lelouch has his moments in Code Geass. His response to Rolo murdering Shirley (Because she mentioned Nunnally, the one person Rolo wanted dead) is to wipe out the entire Geass Order. While there were undoubtedly some monsters in that number, he still has his minions slaughter kids. Tykebombs, yes, but kids.
The part where Charles kills his brother V.V. for lying to him for the second time seems like disproportionate retribution, even considering the pact they had, but doesn't seem so disproportionate once you find out what V.V. lied about the first time.
While Lelouch's reasons for taking out the Geass Order were indeed disproportionate, it's not like he wasn't going to do it eventually. Remember the Order's main goal was to research and weaponize Geass so they could control world affairs from the background (as demonstrated by Rolo's activities), which pretty much made them enemies of Lelouch from the get go (V.V.'s kidnapping of Nunnally and supporting Charles and Britannia notwithstanding). Besides, as noted, those kids were pretty much walking, breathing weapons anyway, so as cruel as it is to kill children, it wasn't like they were entirely unsanctioned. Especially if, again going by Rolo's example, the Order had those kids performing assassinations in their lower digits.
More of a villainous example, but in Deadman Wonderland, after Shiro breaks Genkaku's beloved electric guitar, the next time he meets her, he captures her and orders his men to cut her up and rape her. (Part of it was also because he seemed angry and jealous that she was Nagi's friend, but mostly because of his guitar.)
The entire point of Death Note is Light's belief that capital punishment (generally via heart attack) is the only appropriate punishment for ANY crime. His idea of "crimes" range from murder to... laziness. That's right, he was planning on punishing people who don't work hard enough with death. Light IS this trope.
When Frieza's henchmen are trying out for the Ginyu Force, Captain Ginyu kills a Mook called Captain Strong because he is also a captain ("There's only one captain on the Ginyu Forces and that's me!" He then kills another of Frieza's henchmen because he touched a Dragon Ball (which Ginyu forbade them to do), and does the same to the rest of the mooks trying out because they lack the style to be on the Ginyu Force.
Actually, the "only room for one captain" line is dub only. In the original? The guy's first-run tryout pose isn't quite up to snuff.
Dr. Gero wanted revenge against Goku for destroying the Red Ribbon Army. To that end, he created a series of androids that turned one timeline into Hell for twenty years and nearly destroyed the solar system in the main timeline. The Disproportionate Retribution comes into play when you considered that Gero's former boss, Commander Red, wanted the Dragon Balls and sacrifice numbers of his own men so he could become taller. Granted, Gero didn't know that, but it is still scary to consider that a petty goal of one minor villain caused so much trouble.
Broly from the eighth movie hates Goku with a murderous passion because shortly after they were both born, Goku's crying bothered him.
It gets to the point where he so hates Goku, that he's willing to murder Goku's sons in his second movie because he thinks they're both Goku!
In Dragon Ball GT, a couple of teenagers call Vegeta a geezer while trying to flirt with his daughter. Vegeta ripped off their steering wheel and sent their car plummeting into the ocean. All things considered, they probably got off light.
Let's just face it, Vegeta's a recurring example of this trope. At the end of the DBZ series, at the tournament when a guy heckles him, he punches him in the face hard enough for him to forfeit the match.
Beerus from Battle Of Gods visits Earth, and says that he won't destroy it provided nothing annoys him. After Whis tells him about how good pudding is, he wants some. Buu wants all of the pudding to himself. So Beerus and Goku get in a fight with the fate of the entire planet resting in the balance.
A flashback in Elfen Lied reveals that Lucy killed Kouta's sister and father just because Kouta lied about his cousin's gender.
Actually, it was less the lie than the thought of Kouta expressing romantic feelings towards someone else. After hearing Kouta say the cousin he was going with was a boy, Lucy thinks to herself that she would have killed Yuka in a fit of jealously if she'd known she was a girl. So regardless if whether Kouta had spoken the truth or not, someone was still bound to get killed.
Excel Saga played this for laughs when Department of City Security head Dr. Kabapu forced his team to patrol the city in Sentai suits. Cue Stuff Blowing Up for minor offenses, like littering and flirting.
In Eyeshield 21, this is Hiruma's entire stance. To quote: "Attack attack and attack! Two eyes for an eye, two teeth for a tooth!" One wonders what sort of karmic retribution he's expecting for all the stuff that he does.
In Fist of the North Star, the villain Amiba decides to imprison Toki, get plastic surgery to look just like him, impersonate him, and perform horrible experiments to ruin his good name... because Toki slapped him in the face once. And not even deliberately, at that!
Hokuto Shinken, due to its horrific effects when it is used to kill, can often be seen as disproportionate for many of the bad guys that Kenshiro uses it on.
Sōsuke Sagara of Full Metal Panic! breathes this Trope. Strangers who so much as looks at Kaname tend to wind up face-down, on the ground with a gun on the back of their heads, and Sagara preparing to "interrogate" them.
An example from the first episode of Fumoffu, when Kaname is kidnapped by some punks. Sōsuke tortures one of the gang members to find out who every single member of the gang loves the most.
Nakago from Fushigi Yuugi. The reason behind almost everything he does is because of this. He blames Kutoh for the death of his mother, only friend Tarlia (Seiran Den) and the sexual abuse he suffered as a child. He claims he 'wanted revenge on the Heavens that had given [him] hell.'
Also Suboshi. After Amiboshi dies, he blames the Suzaku warriors and to 'get his revenge' he kills Tamahome's family.
In one of the most disgusting examples of this trope, an abusive man in Gantz beats his girlfriend's two year old son to deathfor eating the last pudding cup.
Sumire/Shiwasu Mina in Getsumen To Heiki Mina decided to declare herself Supreme Queen of Earth by forceful takeover and to put a fellow team member out of business just because she was losing against her in the overall team rankings. Just a little overboard there...
Giant Robo: The someone enacting this trope is actually the main cause for most of the events in the OVA. It turns out that Dr. Van Vogler, the Mad Scientist who nearly destroyed the world in the tragedy of Bashtarl actually wanted to stop this disaster before it even happened; his colleagues just decided to blame him since they managed to get out of there. So his son decided to use the Anti-Shizuma Drive to exact revenge on the world that "ignored the truth" by destroying society.
In Gon, this is Gon's core attribute. He frequently dispatches creatures that have attempted to eat or harm him in particularly cruel ways, such as beaching a shark that has swallowed him and feeding it a small piece of banana as it suffocates to death.
One of Gundam SEED's main villains, Muruta Azrael, the leader of anti-Coordinator terrorist organization Blue Cosmos, was picked on by Coordinator bullies when he was little. His answer to that as a grown-up who should have known better? To try and annihilate every single Coordinator from the face of the universe.
ZAFT's reaction to the Junius 7 attack. Deploy N-Jammers on the Earth and shut down every single power plant. That includes the ones belonging to ZAFT's allies on Earth.
Speaking of Gundam, there's also Camille from Zeta Gundam. His career as a pilot started because some space-fascists made fun of his name. In real life, there are a few extreme examples of kids who got pushed around and then took a gun and shot up the school. Camille takes a Gundam and shoots up a space colony!
Then there's Char Aznable from Mobile Suit Gundam who takes it upon himself to avenge his father's death by killing all of the Zabi family, despite no full proof evidence coming forth that Degwin really did murder Zeon Deikun. It can be argued that Gihren was a monster and Kycilia was The Baroness. However, the murder of Garma Zabi, Char's own best friend, definitely counts. Seeing that Garma was actually a really decent guy to both friend and foe and trusted Char completely. Char's own sister, Sayla, comments in disgust about Char's revenge. And later on Char himself even admits it was wrong to take Garma's life and that he isn't motivated by revenge anymore.
For what it's worth, one of the original unaired episodes of MSG (specifically the ones that were removed due to the series being shortened) depicted Degwin meeting Revil aboard the White Base to discuss armistice, only to encounter Sayla and, upon recognizing her as Artesia Som Daikun, go into a frenzy begging her for forgiveness for murdering her father.
You think Garma's death is bad, try Char's actions in Char's Counterattack: he dropped asteroids on Earth and tried to cause nuclear winter (which ran counter to his father's ideals of preserving the Earth) simply to have a final battle with Amuro Ray. That doesn't stop Zeon fans from claiming Char was in the "right" throughout, either through the Earth having it "coming" over the OYW and beyond (9 times out of 10, the Zeeks are usually the ones to start said wars) or Char was legitimately trying to bring peace to the Earthsphere. The latter conveniently omits both human nature and the fact there were other militarized spacenoid factions besides Char's Neo Zeon, namely the Jupiter Empire and Buch Kozern (the latter of which would later become the Crossbone Vanguard). And that's not discounting the fact Char would have killed the Zeon remnants on Earth alongside everything else.
Over in the universe of After War Gundam X, we got the Frost Brothers. All of their actions? Was because the Earth Federation labeled them as Class F (Fake) Newtypes. note They had amazing telepathic and empathy towards each other, it wasn't enough to use the Newtype Bit System. The Federation were a bunch of dicks in that universe, too.
In Gunslinger Girl it was once mentioned that Elsa tried to break a waitress' arm because she almost spilled water on her Fratello.
Heavy Metal L Gaim: Gablet Gablae threw himself into the task of destroying The Hero Daba and his companions, his obsession driving him to obsessively and relentlessly chase them through space and to another planet, engaging in countless mecha duels with Daba and (being defeated and humiliated in every single turn, but that is another story) What did they do to him? Having the gall to demand that he paid the food that he had stolen.
People who got sent to Hell in Hell Girl are largely deserving of what they get, if not for what they have done to the aggrieved personally. As the series goes on it becomes increasingly clear that you can get sent to Hell just for looking at someone the wrong way.
A few episodes of Jigoku Shoujo Futakomori (Hell Girl 2nd season) portray this trope. Also happened in an episode of Jigoku Shoujo Mitsuganae (Hell Girl 3rd season).
One target in season 3 gets sent to hell so the client can avoid potential minor embarrassment.
In Higanbana No Saku Yoru Ni, when Nonomiya is blamed for breaking school equipment, he retaliates by taking pictures of Yoko which ultimately turns the school against her and they make her into their plaything. She kills herself and her soul is then eaten by The Principal.
In Higurashi no Naku Koro ni, Onryu punishes Shion by having three of her finger nails pulled off because she ran away from boarding school.
In the second, '80s Himitsu no Akko-chan series, Akko-chan breaks her Secret Identity by carelessly letting her friend know of her magic mirror and her shapeshifting abilities. The Spirit of the Mirror decides to take away her powers... along with her reflected image, thus forcing Akko-chan to hide her peculiar predicament. Thankfully, everything gets better.
Kenichi: The Mightiest Disciple has Odin, the leader of Ragnarok, who got started on the path of evil as a child when he didn't get the pin he wanted out of a vending machine, but Kenichi did. He fought Kenichi over it, lost, and has been bitter about it ever since in part because Kenichi wanted him to have the pin anyway.
Natsumi of Keroro Gunsou is this trope and then some. Yes, she is sharing her house with an alien frog bent on world domination but she loves beating him for anything that slightly annoys her. Forget to wash the dishes? Beating. Say something insulting about her, even though she always calls him a stupid frog? Beating. Look at her funny? Beating.
In response, Keroro himself sometimes goes into this when he plans revenge against Natsumi. One episode has her throw soybeans at him and call him an oni, which is admittedly nasty—but not nasty enough to turn her into an oni and relentlessly bombard her with soybeans until she surrenders the household.
Oburi from Kite sets himself up for Laser-Guided Karma example of this trope. After his new jacket is dirtied by a wet basketball that accidentally hit him, Oburi shoots the basketball much to the anger of the two children that demanded the ball back and were mocking him, especially the little girl. At the end of the film the little girl shots and kills Oburi while he's walking by to meet up with Sawa.
Both the grievance and the response are delivered accidentally in Kyou No Go No Ni's first episode. When Yuki and Megumi get hit on the head (accidentally) by two high-bouncing "Superballs", and then hit again on the upbounce of another round, cue an argument ending with Yuki accidentally slipping on said superballs in such a way as to deliver a perfect Groin Attack to Ryouta. Needless to say the matter is considered settled after that.
Love Hina is full of this trope. So Keitaro ends up walking in at a time that he shouldn't, so he gets beaten up and humiliated by the residents (all female) at the Hinata inn (as well as at least one Death Threat). Said incidents include when they are changing or at a bath. Even when it is actually one of the girls who walks in on Keitaro when he's changing, he gets beaten up anyways.
Marvelous Melmo has the titular heroine, a 9-year old girl forced to care for her even younger siblings because of her mother's death receives a box of magical candies able to age her to adulthood and de-age her, with the express purpose of being able to care for them. However, since the angels responsible for her take them back when she abuses her power for selfish reasons (date a guy in his late teens, using the added shape-shifting abilities of the candies for making things easier...). At the very same moment, Melmo had just turned herself into a dog, and as such she gets unable to properly care for her siblings or interact with every human soul, even risking to be captured and "put to sleep". The whole while the angels and Melmo's dead mother, in Heaven, argue about Melmo's fate. Eventually the punishment gets partly amended, becoming more proportionate: Melmo's power is restored, thus making her able to resume her human life again and care for her siblings, but with a finite number of transformations, thus forcing her to be more careful.
The fate of several girls in Master of Martial Hearts: if the sheer fact that every fight in the Platonic Heart tends to turn into a death match, it gets worse when you're made aware that actually the losing Action Girls suffer A Fate Worse Than Death itself. They're actually saved, nursed to health and then mindraped to the breaking point and sold into sexual slavery. Just to get sure, many of them get their voice box removed, thus explaining how one of the previous generations loser, after escaping her destiny, became little more than the resident Cute Mute and harmless mom. Tinged with Misplaced Retribution, since Natsume, the daughter of the aforementioned Cute Mute, organized a second edition of the Platonic Heart, thus reaping a whole bunch of completely random strangers, just to lure out the daughter of the organizer of the tournament costing her mom her voice and freedom.
Natsume and Miko's grandfathers killed the families of Aya's parents, so they started the Martial Hearts tournament specifically to target their children. One generation later, Natsume and Miko themselves, upon learning what the fuck had gone down, orchestrate the aforementioned copycat crime ring just to get back at Aya for what had happened to their mothers. This fucks up her brain so badly, the series ends with her trying to put an end to the Cycle of Revenge once and for all before it gets any worse than just "an eye for an eye [leaving] everybody blind".
Dr. Hell from Mazinger Z killed a dog when he was a little child because he thought the mutt was glaring at him. You could tell his sanity was already very strained back then. Also, he was abused by everybody when he was young, and he thinks to Take Over the World and enslave the humanity is a proper punishment for wrongs that were made several decades ago for other people.
My Bride Is a Mermaid: Lunar hates Sun and constantly tries to make her life hell because Sun beat her in a singing contest when they were kids.
Narutaru's villains love this trope. For starters, Satomi Ozawa develops a murderous grudge against the heroine that started just because she made fun of the name of her school. Later in the manga, Naozumi Sudo shoots two delinquents to death just for throwing a bag of trash in a river...
In Naruto, Madara Uchiha wanted to continue the war with the Senju when the two clans had gotten tired of fighting and banded together to create Konoha. The Uchiha family rejected him as a warmonger, and Madara elects to get even with this "betrayal" by assisting Itachi in killing the entire clan.
And it seems that Uchiha Sasuke is following after his ancestor in the 'disproportionate retribution' department. How? Well, after Finding out that Itachi was under orders by Danzou, Sarutobi, Koharu, and Homura to execute the Uchiha clan for treason and an attempted coup that would result in a costly civil war, he apparently decides to MURDER EVERYONE! Danzou, Homura, Koharu, the villagers of Konoha (who had no idea about the attempted coup, much less that Itachi's genocidal actions were sanctioned), innocent samurai who are only doing their job, etc. Apparently the only way to make everything better is to go on a genocidal rampage that would make Pain green with envy.
Also, on one occasion when Jiraiya was caught peeping on Tsunade bathing in his younger years, she proceeded to break both of his arms, six of his ribs, and ruptured a number of his organs as punishment. Yamato even said Jiraiya came very close to dying that day.
In fact, Jiraiya himself admits that's one of TWO times he came close to dying, with the other being Naruto losing control of his Kyuubi-mode.
Danzo could be a Well-Intentioned Extremist version of this. He had a very black and white viewpoint about how ninja should operate, to the point that seeking a Heroic Sacrifice is one of the best ways to prove one's worth. In his backstory during his death, he has the slightest of hesitation to fill that role during the last war. The Second Hokage refuses both his and Sarutobi's offers in order to do it himself, picking Sarutobi as the third. What does he do as retribution? He creates a martial faction of the Anbu which he uses to hide numerous secret enhancements to his body which came as a result of connections to known criminal Orochimaru, all of which lead up to him using mind control in order to take control of the village and eventually attempt to control the ninja world. He's found out, however, and is told that if he had done things nicely, he'd have probably gotten his way anyway, but because of his brainwashing, he can't be trusted. What's worse, before his hacking into being Hokage, he waited while Pain was destroying the village. If Naruto hadn't won the fight, there wouldn't have been anything left for him to rule over in the first place.
Years before the events of the main story, due to some men from the Hidden Mist village abducting Rin and turning her into the Three-Tails' Jinchuriki, and ultimately being responsible for her death, Obito Uchiha, posing as Madara, Mind Controlled Yagura, the fourth Mizukage. Under the influence of said mind control, Yagura essentially forced innocent children to graduate by murdering one another, and then perpetuated the Bloodline Massacres, resulting in the nigh extinction of several clans (including Haku's and Kimimaro's) and ostracizing the surviving Kekkai Genkai users, forcing them into hiding for fear of being killed. Becomes even more Harsher in Hindsight when we learn that Madara was behind the Hidden Mist's role in Rin's death, all in order to get Obito under his control — Obito condemned innocents for something neither them nor their village had anything to do with.
In One Piece, the island of Ohara was subjected to the Buster Call, which is an assload of warships pelting the place with giant cannons until there's nothing left. Their crime? Researching the history of the world.
It is disproportionate in that everybody but Robin was blown to smithereens, including non-researchers, but the subject matter did contain some information which the World Government didn't want out. It's implied that the government didn't put much effort into hiding their displeasure of Ohara's research.
Heck they even ruined Robin's childhood because they think she might know hot to read Poneglyphs (she can but they didn't know that at the time).
Near the beginning of the series, Morgan decreed that anyone who tried to feed a prisoner tied to the cross in the courtyard would be punished for the prisoner's crime. A little girl, not eight years old, would have been executed for trying to feed Zoro if Luffy hadn't defeated Morgan.
Morgan thrives on this trope, considering his Hair-Trigger Temper. Later on, he has a couple of his soldiers stand up a statue of himself by pulling it up with ropes. One of the soldiers accidentally pulls his rope too hard, barely damaging the statue's hand as it bumps on a nearby spire. The poor guy tries to apologize, but in Morgan's eyes, this is a sign of disrespect and is nothing less than a traitorous activity that'spunishable by death!
In the flashback to Luffy's childhood, Saint Jalmack sinks Sabo's boat and possibly kills him for cutting in front of the ship the World Noble was on. He could have justified it with Sabo's pirate flag, but he gave the crossing paths excuse higher priority. Hence this trope.
When Luffy punches a World Noble named Charlos for shooting Hachi, Charlos's father calls in the Marines, including Admiral Kizaru, to the island, and then declares his intention to starve the men of the crew to death while working them as slaves and have the women stuffed, overlapping this with Knight Templar Parent and Moral Myopia.
Before that, Charlos kicked over a wounded man who was being transported to a hospital and shot one of the paramedics carrying him because they dared to not bow before him as he walked by. If that wasn't bad enough, he kidnaps the wife of the man because he found her pretty and wanted her to be his wife..Yeah.
Charlotte Linlin AKA "Big Mom" (one of the Four Emperors) provides protection to any country, but only if they give her payment... in sweets, that is. In the case of Fishman Island, it had to produce ten tons of candy monthly for Big Mom. With that said, would she really be willing to penalize an entire country for not giving her sweets on time? Yes, she would, by obliterating it!
Baby 5, one of Doflamingo's underlings, is known to appease someone whenever she is needed. Thus, all eight of her fiances were men who somehow "needed" her, not because she actually loved them. These men were also quite obviously sleazes and swindlers taking advantage of her. While it would make sense why Doflamingo would kill them (or else Baby 5 would have gotten attached to them), it does not make sense for him to kill them andburn the residing island to the ground.
Akainu killed a marine officer just because he wanted to leave the battle so he could see his family.
Subverted in the Dressrosa arc: after Doflamingo initiates his "Bird Cage" plan, he forms a blacklist of twelve people he wants dead, assigning bounties on their heads. Usopp gets a bounty of 500,000,000 Beli, which initially seems way overblown considering he's one of the weakest, if not the weakest of the list. However, Doflamingo didn't assign him that high a bounty because of his strength, but of his role: because he knocked out Sugar, all the people she had turned into toys returned to normal and the truth behind Dressrosa was revealed, putting Doflamingo in very deep shit.
Played straight with Doflamingo's actual motives for his activities as a pirate — which seems to be par for course for the Celestial Dragons. Doflamingo's father apparently grew tired of the decadence of Mariejois, and decided to forfeit the family's titles as World Nobles in attempt to live the normal, commoner life. Doflamingo despised this decision, so use to the broken privileges bestowed upon the descendants of the twenty kings who found the World Government, and eventually ended up killing him two years after his mother died by illness — something he blamed on their commoner lifestyle. However, when he and his brother attempted to return to Mariejois, the World Nobles rejected their plea, considering them to be a part of a "family of traitors". Doflamingo, angered by this decision, swore to destroy the entire world they lorded over in retaliation. His behavior is more or less alike to that of a spoiled child who didn't get what he or she wanted — so pathetic, that the only reason why he's such a threat is because he's downright psychotic.
In Paranoia Agent, Tokyo is leveled due to Tsukiko Sagi lying about how her dog died when she was in grade school.
Pokémon's Harley comes in seemingly innocent in his debut episode and acts all nice to May, a fellow competitor. Then, May makes a few innocent comments (calling his Cacturne scary and saying that his cookies aren't half bad), which causes him to apparently change his goal in life to humiliating her at every contest that they participate in.
It's even worse in Japanese, where his reaction is to her Verbal Tic.
He acts as something of a borderline parody of the trope, continuously trying to destroy May throughout the show for minor slights like beating him in a battle. In a later episode he finally reveals the deepest reason for his raging vendetta, that being, as a kid he once got part of his meal stolen by a girl who kind of looks like her and even that may have been made up.
Dawn has ended up in a similar experience with one of her rivals, Ursula. Why does Ursula have a vendetta against Dawn? One of Dawn's Pokémon didn't like Ursula's Poffins.
No mention of Paul, who feels the best way to prove himself a better trainer than his brother (who lost to Pyramid King Brandon in a Curb-Stomp Battle) is to crush the morale of everything he can possibly reach?
James has shades of this. He really likes his bottle cap collection. When it had been (accidentally) stolen by a trash-collecting robot, he tried to steal the Sunnyshore Tower. In other words, he tried to steal a bloody skyscraper. What truly seals the craziness is that that was Team Rocket's evil-plan-of-the-week...and Jessie and Meowth were still freaked out at James' sudden gung-ho attitude!
Back in Johto, the Terrible Trio stole the Crystal Bells and accidentally break one of them while running off. What happens? Every last wild Pokemon attacks not just Team Rocket, but any human in sight including Ash and the gang, who didn't do anything!
Way back in the beginning, Ash ended up in a perfumery in Celadon City and ended up getting banned because he insulted the perfume. Not so bad, but the perfumery was actually the Celadon City Gym and the person who banned him was the Gym Leader, Erika. Thus, his Pokemon journey nearly came to an end (never mind that in kicking him out Erika was in violation of gym leader protocol, as Misty soon points out) because he insulted perfume. When Team Rocket got banned, they responded by not only helping Ash get in (in the guise of a girl), but also by trying to burn down the gym.
Then there was the little incident in Johto (Azalea Town to be precise). The folks there are apparently so fond of Slowpoke that when Ash simply stepped on a Slowpoke's tail, it seemed everyone in town was after his head before he could explain it was an accident. (Fortunately, everyone forgave him once he helped Kurt save the Slowpoke in the caves.)
In Pokémon Special, the Sinnoh Trio make a lot of noise in Mt. Coronet's caves. Cyrus feels that burying the three twelve-year old children in a rock slide is the appropriate response.
The case: Ranma has shown up at the Tendo Dojo and plunged it into chaos by revealing he's a boy who's been cursed to turn into a girl when splashed with cold water. The crime: in response to Akane's various derogatory comments, primarily accusing him of being a pervert for seeing her in the nude when she walked in on him taking a bath, Ranma declares it's no big deal for him to see a naked girl, as he can just turn into one anyway, and then adds in an off-hand matter that his female form is better built than Akane is. The response: Akane grabs the table and belts Ranma over the head with it from behind, knocking him out cold.
The case: Ranma, in female form, has been kissed by Mikado Sanzenine. The crime: Ranma is actually a straight boy, with Mikado not knowing either that it was Ranma's first kiss or Ranma's true identity. The response: Ranma (who has enough Super Strength that he can split boulders without trying too hard) turns into a male and hits Mikado over 500 times leaving Mikado unconscious on his feet.
The case: any outsider woman has defeated a female member of the Joketsuzoku. The crime: defeating the female equivalent of one of the closest things Ranma 1/2 has to a Proud Warrior Race Guy. The response: a symbolic Kiss of Death, followed by the defeated Joketsuzoku pursuing the outsider all over the world until one or the other of them is dead.
The case: Ranma has distracted Happosai, causing him to get hurt. The crime: Ranma's interference in one of Happosai's pantyraids allowed the angry women to catch and beat up the Dirty Old Man. The response: Happosai burns a moxibustion on Ranma's back that leaves him weak as a baby, then distributes fliers about how Ranma is weak all over town, gloating to Ranma that this means his various enemies will seriously hurt and perhaps even kill him, without Happosai needing to lift a finger.
The case: Ryoga has hit Ranma with a Koi Rod of Love, causing Ranma to become increasingly infatuated with Ryoga, and then roughly stripped Ranma to check for the telltale mark of the rod. The crime: Ranma has, as per the koi rod's effects, become infatuated with Ryoga and mentions Ryoga's previous stripping of herself when Ryoga roughly rebuffs her advances, causing him to become upset and tell her off. The response: Ranma turns back into a male and pulls the "typical outraged female" act in the series, beating Ryoga up.
Subcrime: Ranma grows steadily more enamored with Ryoga. The response: Ryoga bundles the sleeping Ranma up in a bag and wanders off into the woods, digging a grave and getting ready to kill Ranma and bury the body here so Ryoga can both be free of Ranma's flirtations and have Akane to himself.
The case: when Ranma reveals the magic of the Koi Rod is so strong that she can only think I Want My Beloved to Be Happy and will let Ryoga kill her if that's what he wants, Ryoga hesitates. The crime: Ranma takes Ryoga's hesitation to deliver the death blow as a sign of affection and gently kisses him. The response: Ryoga resumes trying to kill Ranma.
In Ryoga Inherits the Saotome School, Genma practically disowns Ranma, takes Ryoga as his student, trains him to take over the Saotome School of Anything Goes Martial arts and become Akane's fiancé', while teaching him Ranma's weaknesses and arranging a fight between the two in order to publicly humiliate Ranma. All because Ranma ate a manju pastry that Genma was saving for after work.
RO-KYU-BU! shows just how far a school's administration is willing to go to quash suspected pedophilia amongst its students. If even one member of any club so much as makes out with a girl that's so much as three years younger than he, you can say goodbye to the entire club for the next year, and the offending party is forever branded a traitor to his club. This happens at the very start of the series, where Subaru's plans to play high school basketball are derailed by the team captain's alleged actions.
In Rosario + Vampire, everything Gyokuro did was because her husband liked his mistress Akasha more than her.
Sailor Moon S: Mimet stole Telulu's job from her. Telulu's response? To send Mimet falling into a void of nothingness. Which either kills her or traps her in darkness for all eternityLaser-Guided Karma since Mimet did the same thing to her predecessor Eudial by sabotaging her car. In-Universe, Sailor Moon looked utterly horrified at Mimet's fate.
In Saint Beast, Zeus' insane punishments are made all the more clear by the Double Standard treatment certain angels get. Shiva leads a demon into heaven to kill Shin and gets a warning. Judas and Luca start a war against Zeus and get banished to hell. Those three angels who happened to be really arrogant? Purged, and their resentful ghosts trapped in a dark pit.
School Days has become famous for endings where at least one brutal murder takes place among the three teenage main characters — either for sleeping around or just for being the hypotenuse.
Lina Inverse, main character of Slayers, does this a lot — sometimes she seems to have only two levels of punishment: shouting, and blowing things up. It's primarily this willingness to fly off her head over little things and react by throwing around Sphere of Destruction type spells that gives her such a bad reputation. The biggest examples are her blowing up a restaurant for stepping on her own sardine (amidst complaints saying that she didn't want it in the first place), and nearly drowning Amelia in a hot spring after the latter makes an innocent joke towards her.
This is woven into the premise of Special A. Hikari lost a wrestling match against Kei as a kid, which was apparently enough to turn her into a determinator set on beating him at something. Unfortunately, most of the time for her, Failure Is the Only Option.
The supposed god Tezcatlipoca in the manga version of Spriggan.
In the first chapter of Tokyo Mew Mew, Zakuro breaks a girl's arm simply for bullying Retasu in a rather petty manner.
In Musou Kakyou: A Summer Day's Dream, Patchouli Knowledge, already rather stressed out due to Reimu Hakurei, the protagonist and resident Miko, interrogating her about her donation box which was stolen from her shrine, gets hit in the face with one of her own books, thrown by Aya during a heated argument with Marisa. Patchy gets very pissed at this and decides to take it out on Reimu. After a short scene with Sakuya and Remilia, we cut back to the library and Patchy is busting out "Sun Sign: Royal Flare," one of her more powerful spellcard attacks. Reimu herself doesn't exactly hold back in her retaliation either.
In 20th Century Boys by the same author, second Friend is ready to annihilate mankind as "unworthy to live" because one of his childhood friend once committed a petty theft and let him take the blame. They were about 9 years old at the time. The consequences were that Friend was symbolically executed and everyone pretended he was dead. This was done so thoroughly that, as adults, everyone from that clique thought he was really dead. Which should be considered Disproportionate Retribution as well.
In Urusei Yatsura, Ran is always thinking of new ways to torment her initially oblivious friend, Lum, because Lum constantly got her in trouble as a child (sometimes on purpose, sometimes not, but never maliciously) and accidentally stole the guy she likes. She even takes this so far as to help her rescue Ataru from a rival alien princess in The Movie just because if anyone's going to steal Ataru from Lum, it's going to be her, because at least she has a reason for doing so (unlike the rival alien princess in question), even if said reason is a bit unreasonable.
Wolf Guy - Wolfen Crest: Haguro beat his Noble Demon subordinate Chiba within an inch of his life, biting off his tongue, and then raping him for good measure to the point that Chiba ends up dying from a combination of ruptured organs, blood loss, and broken ribs. Thankfully, Inguami gave Chiba some of his blood which ended up bringing Chiba back to life. Why did Haguro do such a thing? Because Chiba ended up encountering Inugami out on the streets and talked to him for maybe 15 minutes when Haguro wasn't around.
In xxxHoLiC Watanuki and Doumeki accidentally broke a spider web while doing some garden cleaning. The spider took her revenge by stealing Doumeki's eye. Considering that it takes about one hour for a spider to construct a web we could say that she overreacted a bit.
Yu-Gi-Oh! is notorious for this. Yugi was the target of several ill-conceived vengeance plots throughout the various seasons. One particular example had the daughter of one of Yugi's grandfather's friends challenge him because his grandpa "stole" her grandpa's rare card.
Jerkass Seto Kaiba does this to an extreme in the manga version, where he traps Yugi and his friends (and a toddler one of them happens to be babysitting) in "Death-T", a gauntlet of murderous trials and challenges where failing could lead to death. Seriously, hiring professional assassins for a REAL laser tag, electric chairs powered by screams, hiring a SERIAL SLASHER... and the reason for all this? Because Yugi beat him in a card game (which Kaiba himself tried to cheat in.) He claims he spent a billion yen on this place (abount $10 million in American money). The fact that he is Easily Forgiven is just insulting to the readers' intelligence.
Kaiba's revenge wasn't just for his defeat, it was because of the Penalty Game that the Pharaoh put him through after he lost. For the crime of stealing his card and threatening him for it, the Pharaoh trapped Seto in an illusion where he experienced his own death. This was actually perhaps the most merciful that the Pharaoh's Penalty Games have been. In this case, he meant for the experience to help change Kaiba's ways. What actually happened is that Kaiba was traumatized enough to have recurring nightmares about the experience (The fact that Kaiba had been operating on a severe Lose=Death mentality thanks to his stepfather at the time didn't help). In fact, in order to make his revenge more complete, he built a technological version of the penalty game, using holograms, to subject Yugi to. Eventually, the Pharaoh got sick of all the revenge schemes, and just blew up the evil part of Seto's mind. He came out of it a sort of changed man. Granted, it put him into a coma for nearly a year, but still.
Interestingly though, this is played completely straight in the Toei anime since Kaiba doesn't experience the Penalty Game (he escapes by ending their duel monsters game in a draw...somehow). Basically, Kaiba takes this trope Up to Eleven by hiring Game Masters to take down Yugi, and eventually setting up Death-T...because Yugi didn't let him steal the Blue Eyes, and tied him in Duel Monsters. Also worth mentioning that the Toei anime didn't include Gozaburo's abusive child-raising and the on-screen takeover of KC was less The Dog Bites Back and more Seto Kaiba is a power-hungry Jerkass which does away with his Freudian Excuse...you're really just left wondering what this Gozaburo did to piss Kaiba off...
Another had Duke Devlin, a would-be game developer, challenge Yugi to a duel because he thought Yugi cheated to beat Pegasus (which is debatable—Pegasus was already using his Millennium Eye to cheat, first with the Mind Scan, then with a Shadow Game that injured Yugi, so whether or not Yugi and Yami's Mind Shuffle counts as cheating is pretty YMMV) and killed him (which he didn't), thus ruining his chance at getting his designer game produced (the fax green-lighting it came in less than an hour after the duel), with the stakes being his friend's freedom, his champion title, and his right to play the show's Serious Business card game forever. To Duke's credit, he does get the hint and eventually forms part of the show's extended cast, helping out at times.
The punchline is that all of the above cheating methods were never publicized at all, only the final result. Duke was convinced Yugi cheated out of sheer denial that anyone could ever defeat Pegasus fairly.
Duke's reasons in the manga were a bit more justifiable, since he had to do it for his Monster Clown of a father in an act of vengeance for whatever Yugi's grandpa did to his face.
Duke's father is a much stronger example of this. He and Solomon Moto played the Devil's Board Game, whose cursed power aged him immensely when he lost. Thing is, they both agreed to play the game (for whatever insane reason), and the rules of the gamenote take turns rolling a die moving a game piece that number of spaces towards the center of the board. are such that one's opponent has no bearing on who wins the game. One can't take revenge on the Random Number God, so imprisoning, discrediting, and murdering Solomon's grandson, after forcing him to play the Devil's Board Game, was apparently the next best thing.
Yami Yugi does have quite a Disproportionate Retribution thing going on, though, especially in the early manga before Yugi puts his foot down. Most of the people he challenges to Shadow Games are unpleasant, and the games are always fair (that's part of the rules) but still... look at Duel 6, Into the Fire. These guys stole Yugi's group's space and injured Yugi, so Yami blew their leader up with explosives. An extortionist bully threatens Yugi and cheats at the shadow game, so he's made to wallow in a pit of trash while thinking that there's nothing but money raining everywhere. A director uses his authority to lie about Yugi and his friends, so the Pharaoh blinds him (in an ironic way). Hilariously, Kaiba's Disproportionate Retribution is the result of one of the Pharaoh's most merciful Penalty Games. Sure, Kaiba was driven mad by the traumatic experience of feeling his own death, but at least he's still alive and functioning.
Minor example and an aversion in Yu Gi Oh ZEXAL during the two-part Duel Coaster episode. V was about to go ballistic on Yuma because he lost only 400 Life Points from Yuma's attack (and V had used the House Rules of the Coaster to increase his points to far more than he started at) and only backed off because Tron told him to. (Of course, later episodes show V to be an egotist in every sense of the term, so this makes sense in hindsight.)
In the manga Yu-Gi-Oh! D Team ZEXAL, the very unsubtly-named villain Master Evil's motive for destroying the entire Duel Carnival (possibly killing his two henchmen after their deathtrap-based duels failed) was because he was disqualified from the last Carnival. (He claimed it was because his deck was too powerful and opponents fled from him in fear, but the real reason is, he had been cheating.)
An older boy in Yu-Gi-Oh! GX that Judai looked up to used a trap card to stop him from summoning Yubel in a duel when he was a kid. He was fairly upset... so Yubel put him in the hospital. When Judai visited the boy later, Yubel did something that made him scream. Small wonder nobody wanted to play with him, because she kept doing these kinds of things.
And it must be remembered that this was before Yubel's "corruption" by the Light of Destruction, which only served to increase the scope of Yubel's crazed actions, affecting their core nature not at all.