History AlternateHistory / AnimeAndManga

* The ''Kerberos'' saga takes place in a world where Nazi Germany won in Stalingrad. It eventually leads to a total Axis victory... in Europe. Japan still falls in 1945. But it's the Germans who occupy and morph the country into a fascist dictatorship.

* ''LightNovel/ACertainMagicalIndex'' is more of a case of NeverWasThisUniverse due to the existence of magic, but special mention goes to the United States being on its third Hispanic President, the [[https://en.wikipedia.org/wiki/G14_%28nations%29 G14]] having been established, a second Costa Rican civil war having taken place, the existence of the Elizalina Alliance of Independent Nations (a union of nations and countries formerly part of Russia) and a non-nuclear power United Kingdom having retained its long-held animosity against France (in part because they were forced to give up their nuclear arsenal to France by the European Union).

* ''LightNovel/FullMetalPanic'' follows a present day where the Cold War never ended (due to Mikhail Gorbachev having been assassinated, and thus, the political reforms which led to the breakup of USSR never came to pass) and the arms race led to [[HumongousMecha combat mechs on the battlefield]] -- aided along by Black Technology, which comes the Whispered, rare individuals gifted with latent PsychicPowers.

* ''LightNovel/SamuraiGirls'' takes place in a Japan where the Tokugawa Shogunate has remained in power up to the 21st century.
* In ''LightNovel/{{Schwarzesmarken}}'', aliens invade Earth in 1973, leading to a [[EnemyMine NATO-Warsaw Pact alliance]] against them. And then come the [[RealRobotGenre mecha]]...

* The Demon Wars of 1918 changes Japan's history in ''Anime/SakuraWarsTV''.

* [[Anime/FullmetalAlchemist The 2003 anime version]] of ''Manga/FullmetalAlchemist'' is set in [[spoiler:a version of our world where alchemy worked]]. This is revealed when [[spoiler:Edward ends up on the other side of the Gate, which is 1920s England]]. The manga however is a strict AlternateUniverse.

* ''Anime/StrikeWitches'' takes place in a world where aliens invaded in 1939 before World War 2 and forced the world to unite in order to stop them. Also the only way to stop them are by using magical imbued schoolgirls wielding rocket legs with characters like Winston Churchill and George S Patton making cameos. Officially the alternate history goes back further, with BC standing for Before Caeser, the German monarchy never losing power, and giving Japan a more active role in past events.

* ''Manga/{{Ooku}}'' takes place in a Japan where, during the Edo Period, a virulent new strain of smallpox breaks out that's over 60% fatal to men (but nonfatal to most women) and causes a {{Gendercide}}. The manga follows the court politics of a GenderFlipped Tokugawa Shogunate and its all-male RoyalHarem, an incredible luxury in a Japan where fertile men are incredibly rare. [[spoiler:By the tail end of the manga a vaccination programme exterminates the Pox just in time for the forced opening of Japan and the Boshin War, [[WrittenByTheWinners after which the successful (and male-dominated) anti-Shogunate forces destroy all history of the Shogunate ever having been women]].]]

* ''Manga/{{Jin}}'' involves a Japanese neurosurgeon from 2000 being transported back to 1862. He introduces germ theory (nevermind that the germ theory was actually proposed by Girolamo Fracastoro [[OlderThanTheyThink as early as 1546]] and with the works of Louis Pasteur and Robert Koch ''already'' [[CriticalResearchFailure was pretty much the mainstream]] by 1862) and modern surgical techniques to Japan and the West, among other medical ideas. Butterflies abound from his actions. Among the results? [[spoiler: The Meiji Restoration doesn't take place and the Tokugawa Shogunate survives]].

* ''Manga/{{Ooku}}'' takes place in a Japan where, during the Edo Period, a virulent new strain of smallpox breaks out that's 90% fatal to men and causes a {{Gendercide}}. The manga follows the court politics of a GenderFlipped Tokugawa Shogunate and its all-male RoyalHarem, an incredible luxury in a Japan where fertile men are incredibly rare. [[spoiler:By the tail end of the manga a vaccination programme exterminates the Pox just in time for the forced opening of Japan and the Boshin War, [[WrittenByTheWinners after which the successful (and male-dominated) anti-Shogunate forces destroy all history of the Shogunate ever having been women]].]]

* ''Franchise/DotHack'' diverges initially around 2002 with the founding of the UN's World Network Commission in the wake of mounting cybercrime. But the real changes happen when a virus called Pluto's Kiss is unleashed on December 24, 2005, crippling thousands of computer systems worldwide and effectively ''crashing the Internet.'' This provided the [[MegaCorp ALTIMIT Corporation]] virtual monopoly over rebuilding the net and helped set the stage for The World.

* The finale of the manga version of ''Manga/ChronoCrusade'' reveals that it falls under this genre. [[spoiler:Demon's homeworld--a spaceship/fish/...thing called Pandaemonium--is called out of the depths of the Atlantic ocean by [[WellIntentionedExtremist Aion]], which causes a tidal wave that destroys UsefulNotes/NewYorkCity. [[TheLancer Chrono]] goes after Aion to try to stop him, and they end up fighting in Pandaemonium. At some point in the process, it blows up, creating a ring around the Earth that's visible in the sky even in the 1990s.]]

* In ''Manga/{{Zipang}}'', a [[UsefulNotes/KaijuDefenseForce JSDF]] ship travels back in time to WWII, and the temporally displaced crew debates whether they should meddle with history or not, later on stopping one person who desires to do just that.

* Though not intentional originally, the TwentyMinutesIntoTheFuture timeline of ''Anime/SuperDimensionFortressMacross'' tends to play out like this in the present day. As far as anyone knows, a massive alien spaceship did ''not'' land on Earth in 1999, to be rebuilt by the plucky earthlings, inadvertently sparking war between us and [[AttackOfThe50FootWhatever the Zentradi]], causing the annihilation of nearly all of humanity in 2010...

* In ''Manga/TokyoGhoul'', the titular species has existed alongside humanity since at least the 19th century, although no one is sure where exactly they came from. The CCG, an organization created to investigate Ghouls, was founded in 1890.

* ''Anime/CodeGeass'' takes place in a timeline where things went really well for British imperialism; the Celts kicked Julius Caesar and the Romans off the island, Elizabeth I had male heirs, [[UsefulNotes/TheAmericanRevolution "Washington's Rebellion"]] failed... all with the cumulative effect of making "Britannia" the only superpower on the planet as of the early 21st century. They ''were'' defeated by Napoleon, though, forcing them to abandon Britain and relocate to what had been the colonies -- that is, North America, which is ''entirely'' under their control. Napoleon's Europe-spanning empire also laid the foundation for a faux-EU before he died (likely of poisoning by one of Queen Bessie's spies). It bears mentioning that there are certain factors present in the world of Anime/CodeGeass that indicated that perhaps it NeverWasThisUniverse. Such as Sakuradite and Geass itself.

* Combined to an extent with UnintentionalPeriodPiece (as it was made and released during TheNineties but takes place in 2015), the InUniverse backstory of ''Anime/NeonGenesisEvangelion'' was that in the year 2000, a global cataclysm called the Second Impact occurred, killing off large swaths of humanity in addition to causing all sorts of damage to civilization. The most visible UnintentionalPeriodPiece aspect is the tech used in the show (no smartphones, Shinji listens to music on a tape player), which can be justified by how said global cataclysm slowed down development in certain ways (and probably killed off the inventors of said tech).

* ''Anime/ThePlacePromisedInOurEarlyDays'' takes place in a timeline where Japan is divided after losing WWII, between the [[HammerAndSickleRemovedForYourProtection (Soviet?) "Union"]] and the US.

* The finale of the manga version of ''Manga/ChronoCrusade'' reveals that it falls under this genre. [[spoiler:Demon's homeworld--a spaceship/fish/...thing called Pandaemonium--is called out of the depths of the Atlantic ocean by [[WellIntentionedExtremist Aion]], which causes a tidal wave that destroys UsefulNotes/NewYorkCity. [[TheLancer Chrono]] goes after Aion to try to stop him, and they end up fighting in Pandaemonium. At some point in the process, it blows up, creating a ring around the Earth that's visible in the sky even in the 1990s.]]
** The anime ending averts this by ''trying'' to stick to OTL. [[spoiler: It's implied that Aion shot John Paul II.]]
* ''Anime/KikisDeliveryService'' takes places in a Europe where WWII never happened.

* [[Anime/FullmetalAlchemist The 2003 anime version]] of ''Manga/FullmetalAlchemist'' is set in [[spoiler:a version of our world where alchemy worked]]. This is revealed when [[spoiler:Edward ends up on the other side of the Gate, which is 1920s England]]. The manga however is a strict AlternateUniverse.
* ''Anime/ReadOrDie'' takes place in a British-dominant world, complete with hidden superpowers. By the sequel, however, the Empire had completely collapsed, leaving the world at the mercy of various secret organizations and the United States.

* ''Manga/{{Jin}}'' involves a Japanese neurosurgeon from 2000 being transported back to 1862. He introduces germ theory (nevermind that the germ theory was actually proposed by Girolamo Fracastoro [[OlderThanTheyThink as early as 1546]] and with the works of Louis Pasteur and Robert Koch ''already'' [[CriticalResearchFailure was pretty much the mainstream]] by 1862) and modern surgical techniques to Japan and the West, among other medical ideas. Butterflies abound from his actions. Among the results? [[spoiler: The Meiji Restoration doesn't take place and the Tokugawa Shogunate survives]].
* ''Franchise/DotHack'' diverges initially around 2002 with the founding of the UN's World Network Commission in the wake of mounting cybercrime. But the real changes happen when a virus called Pluto's Kiss is unleashed on December 24, 2005, crippling thousands of computer systems worldwide and effectively ''crashing the Internet.'' This provided the [[MegaCorp ALTIMIT Corporation]] virtual monopoly over rebuilding the net and helped set the stage for The World.
* ''Anime/ConcreteRevolutioChoujinGensou'' gives superpowers and giant mecha to everyone, and plonks them squarely after World War II. Political commentary and superpowered battles ensue.
* In ''Manga/TokyoGhoul'', the titular species has existed alongside humanity since at least the 19th century, although no one is sure where exactly they came from. The CCG, an organization created to investigate Ghouls, was founded in 1890.
* The Demon Wars of 1918 changes Japan's history in ''Anime/SakuraWarsTV''.
* ''Manga/{{Gintama}}'' takes place in a world where sufficiently advanced aliens made contact with Japan before the Black Ships did, causing the country to modernize much faster than they did in real life.
* In ''Manga/AstraLostInSpace'', we're led to believe that [[spoiler:its world history diverged from ours sometime in the 1960's, with the Cuban Missile Crisis resulting in WW3 and wiping out a big chunk of the world's population, leading to massive changes in the structure of the world.]] Though [[spoiler: later revelations seem to suggest that there's something up with that history, given that Lina's time frame would set Earth's destruction a mere ''six years'' before the plot kicks off.]]
* ''LightNovel/ACertainMagicalIndex'' is more of a case of NeverWasThisUniverse due to the existence of magic, but special mention goes to the United States being on its third Hispanic President, the [[https://en.wikipedia.org/wiki/G14_%28nations%29 G14]] having been established, a second Costa Rican civil war having taken place, the existence of the Elizalina Alliance of Independent Nations (a union of nations and countries formerly part of Russia) and a non-nuclear power United Kingdom having retained its long-held animosity against France (in part because they were forced to give up their nuclear arsenal to France by the European Union).
** As of NT 9 it is explained that [[spoiler: the current reality the series takes place in is the result of [[CosmicRetcon reality being destroyed and recreated millions of billions of times]], each with its own slight alterations to history and the varying laws of physics that make it different from the previous one. So it is very possible that the universe is still ours but the fabric of reality within it is not any longer.]]
* Combined to an extent with UnintentionalPeriodPiece (as it was made and released during TheNineties but takes place in 2015), the InUniverse backstory of ''Anime/NeonGenesisEvangelion'' was that in the year 2000, a global cataclysm called the Second Impact occurred, killing off large swaths of humanity in addition to causing all sorts of damage to civilization. The most visible UnintentionalPeriodPiece aspect is the tech used in the show (no smartphones, Shinji listens to music on a tape player), which can be justified by how said global cataclysm slowed down development in certain ways (and probably killed off the inventors of said tech).

** As of NT 9 it is explained that [[spoiler: the current reality the series takes place in is the result of [[CosmicRetcon reality being destroyed and recreated millions of billions of times]], each with its own slight alterations to history and the varying laws of physics that make it different from the previous one. So it is very possible that the universe is still ours but the fabric of reality within it is not any longer.]]

* In ''Manga/AstraLostInSpace'', we're led to believe that [[spoiler:its world history diverged from ours sometime in the 1960's, with the Cuban Missile Crisis resulting in WW3 and wiping out a big chunk of the world's population, leading to massive changes in the structure of the world.]] Though [[spoiler: later revelations seem to suggest that there's something up with that history, given that Lina's time frame would set Earth's destruction a mere ''six years'' before the plot kicks off.]]