History AbortedArc / AnimeAndManga

** The series lost a couple of important story elements thanks to the time slot shift for the second season and the {{Retool}} intended to prevent a ContinuityLockout on new fans. This includes an explanation for Suzaku's superhuman abilities (and any possible connection to the Geass) and the possibility of finally revealing C.C.'s name.

* ''Anime/MagicalWarfare'': Plot twists will be suddenly thrown at the viewer as though setting up an impending story arc, only to be forgotten about as quickly as they'd appeared. One of the most blatant examples is when [[spoiler:Ida's sister]] is supposedly kidnapped by the magical equivalent of the FBI: it seems as though the heroes are going to pull off a daring rescue, but instead the kidnapping is never brought up again and the series ends with the viewer clueless as to what ultimately happened to her.

* The animated adaptation of ''LightNovel/MagicalWarfare''. Plot twists will be suddenly thrown at the viewer as though setting up an impending story arc, only to be forgotten about as quickly as they'd appeared. One of the most blatant examples is when [[spoiler:Ida's sister]] is supposedly kidnapped by the magical equivalent of the FBI: it seems as though the heroes are going to pull off a daring rescue, but instead the kidnapping is never brought up again and the series ends with the viewer clueless as to what ultimately happened to her.

* In ''Anime/GundamBuildDivers'', Nanami Nanase expresses enjoyment of GBN in episode 19 and plans to join the rest of Force Build Divers by building her own Gunpla with an extra one intended for Sarah. The very next episode kicks off the final storyline involving Sarah's origins and Nanami is punted to the wayside. Heck, Sarah gets her own Gunpla in the end not connected to what Nanami wanted to give her.

* ''Anime/PuellaMagiMadokaMagica'' ends with Madoka [[spoiler:essentially becoming God with her wish and rewriting the rules of the universe]] so that in this new setting the enemies aren't Witches any more, but tall, robed creatures named Wraiths. The plot of the series is continued and concluded in the third movie, ''Anime/PuellaMagiMadokaMagicaTheMovieRebellion''. This time, however, the enemies are new creatures called Nightmares [[spoiler:except not really, because it's all part of a fake reality which is Homura's witch barrier]] and the Wraiths are nowhere to be seen again, outside of that ''very'' brief and unexplained scene at the very end of the original series.

* In one of the later chapters of ''Manga/{{Beastars}}'' a new character, Kyuu, introduces a martial art called "Imaginary Chimera" where practitioners take strong feelings towards other species and projects them outward into an illusory avatar that's a chimera of the user's species and those they hold said feelings for (hence the name). Legosi proves to be a natural and begs Kyuu to train him so that he can use it in his inevitable confrontation with Melon. However, we know basically nothing about it beyond what you just read, even its practical application in battle, because its existence is completely forgotten about after a few chapters. It was probably dropped because the series was about to be cancelled and it would be cumbersome to develop a new martial art that's never been mentioned up to this point during what was now the climax of the series.

* ''Anime/DigimonAdventure02'' had the infamous "[[BizarroEpisode His Master's Voice]]" (aka "Call of Dagomon") episode. A tribute to the works of Creator/HPLovecraft, the episode ended with Dagomon (a horrifying Franchise/{{Cthulhu|Mythos}} [[CaptainErsatz clone]]) rising up from the sea in [[SinisterSilhouettes silhouette]], with the FindOutNextTime narration promising a future appearance from the beast. Dagomon never appeared again. His role was originally going to be expanded, but [[ExecutiveMeddling meddling from Bandai]] and [[CreativeDifferences disputes amongst the show's staff]] led to the arc being aborted, creating headaches for Digimon fans for years to come. Not even his actual appearance in Xros Wars' [[Anime/DigimonXrosWarsTheYoungHuntersWhoLeaptThroughTime final arc]] has cured it (though that was likely because it was a different individual of the same species in an alternate universe).

* ''Shin'' ''Manga/GetterRobo'' ''Armageddon'' had its original director pack up and leave, taking his plans with him, only three episodes into its thirteen-episode run. Consequently, while the remaining ten episodes do manage to bring the show to a conclusion, a number of plot points that were set up in the initial three were never really resolved. Among these: why Hayato helped Professor Saotome to frame Ryoma for his murder, why Saotome built the Shin Dragon to begin with, and why the Shin Dragon seemed to have the power to devolve the planet.

** When it first began, ''Manga/MobileSuitGundamSEEDAstray'' strongly implied that Lowe Guele's intelligent computer 8 was the learning computer from [[Anime/MobileSuitGundam Amuro Ray's RX-78-2 Gundam]]. Lowe found it in a long-abandoned space capsule that strongly resembled the Gundam's Core Fighter, and it had the number 8 written on the case along with badly smeared and faded text that corresponded to "RX-7". This may have been done because ''SEED'' followed on the heels of ''Anime/TurnAGundam''[[note]]Which outright said that all ''Gundam'' series take place in a single timeline with lots of time in the middle to separate each story[[/note]], but was quietly dropped and 8 had no further significance to the plot beyond being another member of the Junk Guild crew.

** In the ''Best Wishes'' saga, we have a case of an aborted ''conclusion'' to a near-finished arc. The subplot with Team Rocket and the "Meteonite", a space rock with special destructive powers, is built up for several episodes and ''just'' as the epic two-part conclusion to this subplot is about to air, [[DistancedFromCurrentEvents an earthquake devastates Japan and the episodes are pulled from rotation and never referenced again]]. [[spoiler: Various trailers and a synopsis based on leaked information show that it went pretty much how one would expect it to go - with Team Plasma stealing the Meteonite from Team Rocket, the two teams fighting over it, and Ash intervening and having Pikachu destroy it to end the conflict.]] Though even if they ''did'' air, the announcement of [[Videogame/PokemonBlack2AndWhite2 sequel games]] as opposed to the usual UpdatedRerelease third version caused such a shakeup that whatever the rest of the Plasma plotline was meant to be got excised from the main story, completely separating it from the whole Badge quest and TournamentArc.

** In the ''Best Wishes'' saga, we have a case of an aborted ''conclusion'' to a near-finished arc. The subplot with Team Rocket and the "Meteonite", a space rock with special destructive powers, is built up for several episodes and ''just'' as the epic two-part conclusion to this subplot is about to air, [[DistancedFromCurrentEvents an earthquake devastates Japan and the episodes are pulled from rotation and never referenced again]]. [[spoiler: Various trailers and a synopsis based on leaked information show that it went pretty much how one would expect it to go - with Team Plasma stealing the Meteonite from Team Rocket, the two teams fighting over it, and Ash intervening and having Pikachu destroy it to end the conflict.]] Though even if they ''did'' air, the announcement of [[Videogame/PokemonBlack2AndWhite2 sequel games]] as opposed to the usual UpdatedRerelease third version caused such a shakeup that the rest of the Plasma plotline was excised from the main story, completely separating it from the whole Badge quest and TournamentArc.

* ''Anime/{{Pokemon}}'':

* ''Manga/NegimaMagisterNegiMagi'' was going to have a brief sub-arc during Mahorafest featuring Zazie and the Nightmare Circus event, but it was cut because Mahorafest was getting really long as it was (at the time, roughly ''half the manga''). It's implied that Negi ''did'' go to the circus, but we never actually get to see it, thus making the series' most enigmatic character even more enigmatic.

* In ''Manga/DemonSlayerKimetsuNoYaiba'', the ranks within the Demon Slayer Corps quickly fade out of any real importance after the Red-Light District arc despite the main trio of Tanjiro, Zenitsu and Inosuke being pointed as rising 3 ranks ever since they started their career – from 10th at the base as Mizunoto, to 7th as Kanoe[[note]]The second Databook reveals all three of them actually rose up to Hinoe rank by the Infnity Castle Arc, that's just three steps down the Hashira[[/note]] – that’s 10 ranks within the field Slayers and the one above all of them, the Hashira rank; Gotoge, in a narrative sense, basically streamlined the Demon Slayer Corps as "those who are Hashira, and those who aren't", thus all the main boys are measured with is with how close, or how far, they are from being as strong as the Hashira, without anything in-between. [[spoiler:The series ends without Tanjiro, Zenitsu and Inosuke not becoming Hashira but progressing in their strength instead, Tanjiro is outright stated to be a Hashira level slayer by Giyu later, Zenitsu presents feats only the Hashira have (creating a new form, killing a Twelve Kizuki demon), and Inosuke is part of the effort in killing the Upper-Rank 2, but there's no promotion to be had when the whole reason the Demon Slayer Corps existed was to kill all demons, and Muzan dying accomplished that]].

* In ''Manga/DemonSlayerKimetsuNoYaiba'', the ranks within the Demon Slayer Corps quickly fade out of any real importance after the Red-Light District arc despite the main trio of Tanjiro, Zenitsu and Inosuke being pointed as rising 3 ranks ever since they started their career – from 10th at the base as Mizunoto, to 7th as Kanoe[[note]]The second Databook reveals all three of them actually rose up to Hinoe rank by the end of the series, that's just three steps down the Hashira[[/note]] – that’s 10 ranks within the field Slayers and the one above all of them, the Hashira rank; Gotoge, in a narrative sense, basically streamlined the Demon Slayer Corps as "those who are Hashira, and those who aren't", thus all the main boys are measured with is with how close, or how far, they are from being as strong as the Hashira, without anything in-between. [[spoiler:The series ends without Tanjiro, Zenitsu and Inosuke not becoming Hashira but progressing in their strength instead, Tanjiro is outright stated to be a Hashira level slayer by Giyu later, Zenitsu presents feats only the Hashira have (creating a new form, killing a Twelve Kizuki demon), and Inosuke is part of the effort in killing the Upper-Rank 2, but there's no promotion to be had when the whole reason the Demon Slayer Corps existed was to kill all demons, and Muzan dying accomplished that]].

* In ''Manga/DemonSlayerKimetsuNoYaiba'', the ranks within the Demon Slayer Corps quickly fade out of any real importance after the Red-Light District arc despite the main trio of Tanjiro, Zenitsu and Inosuke being pointed as rising 3 ranks ever since they started their career – from 10th at the base as Mizunoto, to 7th as Kanoe[[note]]The second Databook reveals all three of them actually rose up to Hinoe rank by the end of the series, that's just two steps down the Hashira[[/note]] – that’s 10 ranks within the field Slayers and the one above all of them, the Hashira rank; Gotoge, in a narrative sense, basically streamlined the Demon Slayer Corps as "those who are Hashira, and those who aren't", thus all the main boys are measured with is with how close, or how far, they are from being as strong as the Hashira, without anything in-between. [[spoiler:The series ends without Tanjiro, Zenitsu and Inosuke not becoming Hashira but progressing in their strength instead, Tanjiro is outright stated to be a Hashira level slayer by Giyu later, Zenitsu presents feats only the Hashira have (creating a new form, killing a Twelve Kizuki demon), and Inosuke is part of the effort in killing the Upper-Rank 2, but there's no promotion to be had when the whole reason the Demon Slayer Corps existed was to kill all demons, and Muzan dying accomplished that]].

* In ''Manga/DemonSlayerKimetsuNoYaiba'', the ranks within the Demon Slayer Corps quickly fade out of any real importance after the Red-Light District arc despite the main trio of Tanjiro, Zenitsu and Inosuke being pointed as rising 4 ranks ever since they started their career – from 10th at the base as Mizunoto, to 6th as Kanoe[[note]]The second Databook reveals all three of them actually rose up to Hinoe rank by the end of the series, that's just two steps down the Hashira[[/note]] – that’s 10 ranks within the field Slayers and the one above all of them, the Hashira rank; Gotoge, in a narrative sense, basically streamlined the Demon Slayer Corps as "those who are Hashira, and those who aren't", thus all the main boys are measured with is with how close, or how far, they are from being as strong as the Hashira, without anything in-between. [[spoiler:The series ends without Tanjiro, Zenitsu and Inosuke not becoming Hashira but progressing in their strength instead, Tanjiro is outright stated to be a Hashira level slayer by Giyu later, Zenitsu presents feats only the Hashira have (creating a new form, killing a Twelve Kizuki demon), and Inosuke is part of the effort in killing the Upper-Rank 2, but there's no promotion to be had when the whole reason the Demon Slayer Corps existed was to kill all demons, and Muzan dying accomplished that]].

* In ''Manga/DemonSlayerKimetsuNoYaiba'', the ranks within the Demon Slayer Corps quickly fade out of any real importance after the Red-Light District arc despite the main trio of Tanjiro, Zenitsu and Inosuke being pointed as rising 4 ranks ever since they started their career – from 10th at the base as Mizunoto, to 6th as Kanoe – that’s 10 ranks within the field Slayers and the one above all of them, the Hashira rank; Gotoge, in a narrative sense, basically streamlined the Demon Slayer Corps as “those who are Hashira, and those who aren’t”, thus all the main boys are measured with is with how close, or how far, they are from being as strong as the Hashira, without anything in-between. [[spoiler:The series ends without Tanjiro, Zenitsu and Inosuke ever advancing their ranks further, not becoming Hashira but progressing in their strength instead, Tanjiro is outright stated to be a Hashira level slayer by Giyu later, Zenitsu presented feats only the Hashira have (creating a new form, killing a Twelve Kizuki demon), and Inosuke was part of the effort in killing the Upper-Rank 2; there’s no promotion to be had when the whole reason the Demon Slayer Corps existed was to kill all demons, and Muzan dying accomplished that]].

* ''Shin'' ''Manga/Getter Robo'' ''Armageddon'' had its original director pack up and leave, taking his plans with him, only three episodes into its thirteen-episode run. Consequently, while the remaining ten episodes do manage to bring the show to a conclusion, a number of plot points that were set up in the initial three were never really resolved. Among these: why Hayato helped Professor Saotome to frame Ryoma for his murder, why Saotome built the Shin Dragon to begin with, and why the Shin Dragon seemed to have the power to devolve the planet.

* Two different series of cards in ''Anime/YuGiOhGX'' ended up being CutShort (funnily, being based on very similar concepts). In multiple Duels, Judai showed off the existence of HERO monsters under the effects of Metamorphosis, which could tribute a HERO to summon an upgraded version from the Fusion Deck. Two of these upgraded HERO monsters, Neo Bubbleman and Clay Guardian, were utilized in various duels, and it's not hard to guess there would have been more... and then Metamorphosis was banned in real life for being abused in completely different decks, and Judai never used Metamorphosis again because he would now be showcasing cards that could never be played. Later on, he demonstrated the use of NEX, which did the same thing but limited to Neo-Spacians and summoned upgraded Neo-Spacians that could be used to summon upgraded Neos fusions. The card even depicts all six Neo-Spacians in its artwork. Over the course of the series, he used it, again, on two of them, and managed to bring out exactly one upgraded Neos fusion. The other four monsters pictured on NEX never got their upgraded forms.

* ''{{Manga/Bleach}}'' is just filled with these.

* ''Manga/MahouSenseiNegima'' was going to have a brief sub-arc during Mahorafest featuring Zazie and the Nightmare Circus event, but it was cut because Mahorafest was getting really long as it was (at the time, roughly ''half the manga''). It's implied that Negi ''did'' go to the circus, but we never actually get to see it, thus making the series' most enigmatic character even more enigmatic.