[[caption-width-right:300:Partners today. Enemies tomorrow.]]

''2009: Lost Memories'' is a joint Japanese-South Korean sci-fi action thriller from 2002.

It's 2009 in an AlternateHistory where the assassination of Resident-General [[http://en.wikipedia.org/wiki/Ito_Hirobumi Ito Hirobumi]] in 1909 was averted, leading to Japan allied to the US in World War II and therefore retaining its colonial empire in the Asia-Pacific region, including Korea.

Sakamoto, a Japanese Bureau of Investigation (JBI) agent of Korean heritage and Saigo, his Japanese partner try to solve a strange case where [[YourTerroristsAreOurFreedomFighters Pro-Korean nationalist "terrorists"]] attempt to steal a strange archaeological artifact. Initially Sakamoto is valuable to the case because of his ability to communicate with the terrorists. He is later removed from the case when it is discovered that his father had some previous involvement with the terrorist group. Sakamoto's desire to solve the mystery involves threatening the powerful Inoue Foundation. This only makes him more passionate about its resolution and after uncovering more on his own, he discovers that reality isn't how it should be. It then becomes his new mission to restore history to its rightful path.

It has a limited release overseas as seen in Asia and in North America, most of them having official English subtitles and dubs, depending on the country/territory where you purchase the movie.

It was adapted from ''In Search of the Epitaph'', by Bok Geo-il, which has similiar settings, but has way more drama then this.

Essentially ''Film/{{Fatherland}}'' with an Asian slant.

!!Contains examples for the following tropes:

* AlternateHistory: Ito Hirobumi survives his assassination attempt at Harbin 1909. This led to Imperial Japan as an pro-Allies country with the nukes dropped in Berlin. The 2002 [=FIFA=] World Cup games was solely located in Japan only with a few Korean soccer players playing for the Japanese national football team.
* ArmorPiercingQuestion: Sakamoto asks his captor why they're doing horrible things to make fellow Koreans suffer. Her answer was that they're fighting for independence and she asks whether he should treat his cop father as one since he was arrested for corruption [[spoiler:and for covertly supporting the Hureisenjin]].
* BittersweetEnding: [[spoiler:Thanks to Sakamoto stopping or at least distracting Saigo in 1909, An Jung-geon successfully kills Ito Hirobumi as in RealLife, Korea is united by 2009, Sakamoto and his dream girl are a pair on educational billboards among other resistance fighters, an epic victory of the Hureisenjin. On the other hand, the restoration of the timeline required life losses on itself, directly through combat and indirectly by wiping out a whole timeline.]]
* ButterflyOfDoom: The conspirators of the Inoue Foundation explain Saigo thoroughly that he and his family won't exist in a world without a surviving Hirobumi, so that he cannot renounce to follow the call. Considering what the butterfly effect is all about, it's completely {{Justified|Trope}}.
* ChekhovsGun: The Lunar Crescent, the device enabling the devastating time traveling act in the first place. Also qualifies for ArtifactOfDoom.
* CrazyPrepared: The Hureisenjin cell at the start of the movie were aware that the JBI would conduct a breach and would not negotiate with them due to their previous attack on the Japanese Cultural Center, so [[spoiler:they made arrangements for one of their own to get away while the others waste JBI agents. Unfortunately, they didn't realize that a hostage would notice the fake waiter.]]
* CulturePolice: Koreans with perfectly Japanese names like Sakamoto and Takahashi? Kyongsong/Keijo (Seoul) looking like a thoroughly Japanese city with abundant Hiragana instead of Hangeul? Koreatowns in a Korean city? Tokyo must have played an awful one. TruthInTelevision as Imperial Japan did engage in this policy and if World War II didn't start, Korean cultural identity would have been eradicated to the point that it would be seen as a minority language.
* DressingAsTheEnemy: Not really as the enemy considering which side Inoue is on in 1909, but he still kills one of the guards to take his uniform and mesh unnoticed among the other guards at Harbin station as the only savvy Japanese to protect Hirobumi from An's shots. [[spoiler: In vain.]]
* ExtyYearsFromNow: The whole story is to take place a whole century from the assassination (attempt) on Ito Hirobumi and provoked TheGreatPoliticsMessUp by setting the story TwentyMinutesIntoTheFuture.
* FatalFamilyPhoto: Inverted. Sakamoto finds a photo with the guy he shot down in the beginning and his little son whom he's hiding with in the resistance cell near the end of the movie, mere moments before said little son is gunned down (among others) himself by JBI forces.
* ForWantOfANail: The survival of Ito Hirobumi ensuring the hegemional power of Imperial Japan.
* GirlOfMyDreams: Sakamoto instantly dreams of a girl wearing the story relevant crescent on a chain of hers. He gets to know her [[spoiler:when she's approaching him at the "gate" artifact after Ito Hirobumi has been successfully killed and the timeline was restored. One hundred years later, their pairship is documented on a photo at an educational billboard.]]
* {{Government Agency of Fiction}}: The JBI is based on the real-life FBI.
* GovernmentConspiracy: The JBI and Inoue Foundation are obviously in cahoots together.
* HeKnowsTooMuch: Sakamoto's father.
* HeelFaceTurn: Sakamoto [[spoiler:after he realizes that his world is not the real world he's suppose to live in]].
* HeterosexualLifePartners: Saigo and Sakamoto, even at the final showdown
* HistoricalInJoke: After Sakamato answered his father's mentor's question if he knew who An Jung-geun was ("the assassin to kill Ito Hirobumi"), the aforementioned mentor replied that "assassin is an accurate word, because he did indeed succeed", before proceeding with Sakamoto's initiation into the manipulated nature of their timeline.
* IstanbulNotConstantinople: Seoul is Kyongsong, Korea is Choson instead of Hanguk. In Japanese, this would be Keijo and Chosen, respectively.
* JustAStupidAccent: The fact that Sakamoto not only speaks Korean fluently, but also speaks Japanese with a Korean accent, despite the claims that Sakamoto grew up in a totally Japanese environment.
* LaResistance: The Hureisenjin, the Korean freedom fighters
* NamedAfterSomebodyFamous: The employer of police officers Saigo and Sakamoto, the Japanese Bureau of Investigation (JBI). We may assume that the producers didn't care in the first place why a domestic intelligence service needed the word "Japanese" in its name.
** Enh, it's not unheard of; e.g. United States Secret Service (USSS), Royal Canadian Mounted Police (RCMP), Australian Federal Police (AFP).
* PunchClockVillain: The movie is credited for being a Korean production that depicts Japanese people differently and not as complete monsters per se.
* TerminatorTwosome: Saigo and Sakamoto struggling to avoid or ensure Ito Hirobumi's assassination.
* TheGreatPoliticsMessUp: Invoked and failed. According to the movie, the two Koreas were supposed to unite in 2008, enabling Korea to become a new star on the international scene. Flash forward to 2013, Kim Jong-Un has inherited the reign from his father and proved to rule the PeoplesRepublicOfTyranny like it's ever been.
* TheQuisling: Hureisenjin sees Sakamoto as one. And most likely Koreans who decide to be content with direct rule from Tokyo.
* TimeTravel: Part of the story.
* TwentyMinutesIntoTheFuture: layed deliberately.
* WellIntentionedExtremist: You may argue if the intentions justify the means even in the eyes of mosts Korean that put up with being part of Japan by adopting Japanese names (as they explicitly became more extreme as native support decreased for Korean independence), but you may grant the Hureisenjin captors for not abusing their hostages as human shields. They just want to catch the artifact.
* WrittenByTheWinners: In the timeline, the March 1st Movement of 1919 is referred to [[YourTerroristsAreOurFreedomFighters as a terrorist uprising]].
* YouKilledMyFather
** Sakamoto learns during his HeelFaceTurn that the truth about the "corruption" his father did as a police officer and put him on death row was that he worked with the Hureisenjin.
** Sakamoto also gets to know the little son of the guy he shot down in the beginning. He also finds the FatalFamilyPhoto moments before said little son gets gunned down himself, despite Sakamoto trying to save him. This causes [[HeroicBSOD severe]] [[SurvivorGuilt trauma]].
* YourTerroristsAreOurFreedomFighters: The Hureisenjin are outed by the public as [[FarEastAsianTerrorists anti-Japanese Empire terrorists]]. To the oppressed, they are heroes.
* {{Zeerust}}: The video phone booth, outdated even when the movie was made, especially in Korea and Japan. Even dealing in an alternate timeline won't make it forgivable.