History CouldHaveAvoidedThisPlot / AnimeAndManga

* ''Anime/YuGiOhArcV'': Subverted. After Kurosaki hospitalizes Sora, Yuya, Yuzu and Gongenzaka gather up to discuss away from everyone else what they know about their background. When Yuzu brings up that Kurosaki and a friend of his were behind the mysterious attacks on LDS, Gongenzaka angrily asks her why she never said that she knew who the culrpit was, because if she had the LDS would never falsely accuse Yuya and they wouldn't have tried to take over and buy out You SHow Duel School. At this point Yuya figures out that the reason Yuzu said nothing is that he and the other culprit are IdenticalStrangers. Yuzu confirms this, saying that at first she thought that it was Yuya in disguise, but she was confused because [[OOCIsSeriousBusiness he would never do that]]. By the time the misunderstanding was solved the whole business with LDS had passed.

* In ''Manga/OnePiece'', in order to reach Skypiea, the Straw Hats had to track down and ride this massive geyser that can shoot whole islands into the sky. After getting to the White Sea, Ganfor tells them that there are other ways to reach the Sky Islands, and is stunned that the Straw Hats rode the Knock-Up Stream, as it's an All-Or-Nothing shot. Nami goes ballistic on Luffy at the idea that there were safer ways of reaching Skypiea.

* Episode 7 of ''Anime/PokemonTheSeriesAimToBeAPokemonMaster'' revolved around Ash, Brock, and Misty rescuing a trapped Wailord. After spending the entire episode concocting an elaborate pulley with an EnemyMine alongside Team Rocket to boot, Misty realizes at the very end that this could have been over in seconds if they just [[{{Sizeshifter}} put it in a Poké Ball]]. Ash replies that [[ItsTheJourneyThatCounts the important thing is that they had fun]].

* ''Manga/AttackOnTitan'': In Chapter 64, Rod Reiss claims that [[spoiler:Wall Maria could have been saved seven years before if Eren's father didn't murder/devour the crown princess, who had the power to control the Titans]]. In Chapter 66 however, [[spoiler:Historia who is the crown princess's half-sister, she quested why Frieda didn't fight when she could have done so ''already'' when Eren's father warned them about the Titans already breaching Wall Maria. Better yet, why didn't the past inheritors of the Founding Titans for the past 100 years use its powers to free humanity? This is because for the last 100 years, the First King's will was imposed through the royal bloodline that prevents it from being used to fight back the Titans and let the people within the Walls be killed regardless. This explained why Historia remembered Fried yelling at her to not cross the face in a sudden change of behavior. Historia realizes Eren having the Founding Titan's power is a GOOD thing because he won't get said will imposed on him and she defies her father for wanting to continue the cycle.]]

* ''LightNovel/ACertainMagicalIndex'':
** Ouma Yamisaka kidnaps Index (blowing up Touma's apartment, a restaurant, and [[ArsonMurderAndJaywalking Touma's homework]] in the process) and tries to extract knowledge from her mind to lift a curse from a woman he loved. Touma tracks them down and says that he and Index would have been happy to help save the woman if Ouma had just asked for their help. Touma easily lifts the curse off-screen.
** Stiyl Magnus pretends to kidnap Index to lure Touma to him so he can ask for help in retrieving Orsola Aquinas. An annoyed Touma says he could have just asked him directly instead of going through these theatrics.
** Last Order becomes gravely ill, so Accelerator frantically tries everything to cure her. When he runs into Touma, he becomes enraged that [[MisplacedRetribution Touma is a hero, yet is not doing anything to help Last Order]], and attacks him. After a long and destructive fight, Touma defeats him and points out he can't be everywhere at once and didn't know about Last Order's condition, and he would have helped if Accelerator had just asked for his help instead of attacking him. Touma temporarily heals Last Order and gives Accelerator instructions for a permanent cure.

* In ''LightNovel/NyarukoCrawlingWithLove'', a time-traveling alien named Yithka appears and attempts to use a [[FreakyFridayFlip mind-swapping gun]] to "borrow" Nyarko's body, but messes it up and instead swaps Nyarko and Mahiro with each other. After Yithka explains her situation (she needs help dealing with extremists from her time period) and the gang agrees to help, Hasta asks "Why didn't you just tell us that in the first place?" Yithka responds by [[INeedToGoIronMyDog beating a hasty retreat]].

* ''Manga/AttackOnTitan'': In Chapter 64, Rod Reiss claims that [[spoiler:Wall Maria could have been saved seven years before if Eren's father didn't murder/devour the crown princess, who had the power to control the Titans]].

* In ''Anime/YuGiOh5Ds'', Yusei points out to Z-One at the end that [[spoiler:his attempts to save the future from TheEndOfTheWorldAsWeKnowIt could've gone a hell of a lot easier had he simply ''warned'' Past!Neo Domino City of the dangers of Momentum and Synchro Summoning than attempting to destroy the city, like he planned. Especially egregious considering how fresh in the minds of its citizens Zero Reverse was, in Past!NDC]].

* In ''LightNovel/AdachiAndShimamura'', after the main duo move up a year, Shimamura ends up meeting and talking with a few classmates. While Shimamura doesn't really care about those girls, to the point at which she can't even clearly remember their names, Adachi becomes depressed and spends days angsting about the state of their relationship, and whether Shimamura cares for her. Eventually, Adachi realizes that if she'd just talked to Shimamura, the entire misunderstanding would have been cleared up.

* In the first season of ''LightNovel/DateALive'', Kotori's date, which took place in Episodes 11 and 12 could have been avoided completely. [[spoiler:Reine tells Shido at the end of Episode 12 after he successfully seals her that her love meter was already maxed out back when he talked to her in the isolation room and could have sealed her right then and there. However, she tells him that Kotori had her keep it secret so she could go on a date with him anyway. Kotori then claims Reine was lying, and that the readings were wrong, then [[FoodAsBribe bribes her with a dessert]]. Reine then states the readings were off.]] For his part, Shido says he loves her... as a sister, which prompts [[ClingyJealousGirl Kotori]] to kick him as a result.

* ''Anime/CyberpunkEdgerunners'' gets hit with a tragic case of this after the TimeSkip. The final arc stems from a combination of Lucy's ViolentlyProtectiveGirlfriend behavior [[LeaveNoWitnesses in covering their tracks]] [[spoiler:from Arasaka so they don't take David]], and David's own obsession with chroming up pushing his gifted tolerance to the breaking point. [[spoiler:These two misdeeds together catch up to them and lead to catastrophic consequences for the two, culminating in Lucy being abducted by Faraday and David being provoked into installing the cyberskeleton. What could have been a potential HappilyEverAfter for the two falls apart into a depressing BittersweetEnding for the series.]]

* ''Manga/AttackOnTitan'': In Chapter 64, Rod Reiss claims that [[spoiler:Wall Maria could have been saved seven years before if Eren's father didn't murder/devour the crown princess, who had the power to control the Titans]]. In Chapter 65, [[spoiler:Eren freaks out from the revelation that he and his father were indirectly responsible for the deaths of hundreds of thousands, and begs Historia to eat him, obtain the power to control Titans, and kill them off while there's still hope]]. But then [[spoiler:Historia calls her father out on this by asking why her sister, or any of the previous holders of the power for that matter, never lifted a finger to stop the Titans. Rod admits that when someone in the royal family is holding the power, they also inherit the "king's ideology", which makes them not ''want'' to save humanity, since the original king wished for humans to be ruled by Titans. This makes Historia realize that even if she devoured Eren, she wouldn't want to save humanity anymore]].
* ''Anime/BakuganBattleBrawlers'': Honestly, a lot of the plot in the first half of Mechtanium Surge could have been side-stepped easily if Dan had informed his fellow Brawlers about the visions of [[BigBad Mag Mel and Razenoid]] he and Drago had. But, being the idiot he was, Dan made no mention of it and boy, does it come back to bite him in the ass. During his battle with Anubias, Zenthon suddenly appears on the field and nearly kills him. The result was Dan being disqualified from said battle, losing his fanbase and the trust in his comrades.

* ''Anime/BloodPlus'' has the Schiff, escaped bioweapons that really would like nothing more than to live normal, happy lives. Unfortunately, they have a very, very short life span. They believe that drinking Saya's blood will help... and savagely attack her. They eventually ask politely, and Saya gives them some of her blood willingly. Too bad her blood is actually poisonous to them, and it was all set up as a LetsYouAndHimFight. It's actually somewhat justified; having been raised as living weapons, the Schiff have NoSocialSkills, and thus simply asking nicely for something is an alien concept to them.

** In the first season, Fate Testarossa refuses to ask for Nanoha's help in recovering the Lost Logia, even though Nanoha's only objective was that they were safely sealed. [[spoiler:Although this probably wouldn't have worked in the long run anyway, considering the Fate's Mom was going to use them to break reality.]]
*** Fate agrees to Nanoha's help in sealing the six Jewel Seeds in the ocean in Episode 9, dividing them between them... which gets her another whipping from her mother for wasting a precious opportunity.

* ''Anime/ParanoiaAgent'': Sagi Tsukiko [[spoiler:created Shonen Bat]] only to avoid her strict father's scolding for losing Maromi. But Maniwa revealed that [[spoiler:her father always knew the truth: He only went to search for Shonen Bat to avoid the fact that he was so strict and her own daughter feared him, so he lied to the police and took a bat and pretended to search for Shonen Bat to show Tsukiko he cared for her]].

** In ''Anime/SpaceBattleshipYamato2199'' the human characters at some point that the war could have been avoided had [[spoiler:one of ''their'' ships not [[WeComeInPeaceShootToKill opened fire without provocation]] at first contact]], and the whole devastation of Earth could have been avoided by simply surrendering (in fact a number of Gamilas characters openly wonder ''why'' they don't just surrender).

** Most of the Android/Cell Saga could have been avoided if the Z-Fighters had simply tracked down Dr. Gero and put an end to him before he activated the Androids, especially since Future Trunks warned them ''three years in advance''. Bulma [[StatingTheSimpleSolution even suggested they do just that]], but the Z-Fighters unanimously shot that possibility down. Goku and Vegeta are Saiyan {{Blood Knight}}s who can't resist the opportunity to fight a strong opponent, and Krillin suggests it would keep Vegeta in line if they had a common enemy.
** Vegeta does one better in the Cell Saga, by ''intentionally'' allowing Cell to absorb Android 18 and reach his perfect form, simply so that he could have an even stronger opponent to fight against. In fact Cell was ''banking'' on this and fed Vegeta exactly what his pride wanted to hear.

* ''Manga/DragonBallZ'': Throughout the Buu Saga, there were many points at which the heroes could have ended it earlier:

** Most of the Android/Cell Saga could have been avoided if the Z-Fighters had simply tracked down Dr. Gero and put an end to him before he activated the Androids, especially since Future Trunks warned them ''three years in advance''. Bulma [[StatingTheSimpleSolution even suggested they do just that]], but the Z-Fighters unanimously shot that possibility down. Goku and Vegeta are Saiyan {{Blood Knight}}s who can't resist the opportunity to fight a strong opponent, and Krillin suggests it would keep Vegeta in line if they had a common enemy.