[[quoteright:350:http://static.tvtropes.org/pmwiki/pub/images/20thcenturyboys.JPG]]
->''"This symbol is a symbol of friendship."''
--> -- '''Otcho''' in the first chapter of ''20th Century Boys''

''20th Century Boys'' (or, for the final 16 chapters, ''21st Century Boys'') is a manga series created by Creator/NaokiUrasawa, the mastermind behind ''{{Anime/Monster}}''. The plot of the manga spans several decades, from the 1960s to the 21st century, and involves a large cast of characters and several plot twists along the way.

It's the year 1997, and Kenji Endou's life is going to change forever. As a youth, Kenji harbored dreams of becoming a rock star; now, however, he's stuck working in his late father's convenience store (formerly liquor store). On top of that, his older sister has disappeared and has left Kenji to take care of her infant daughter.

One day, Kenji learns that a childhood friend of his, nicknamed Donkey, has committed suicide by jumping off a roof. Shortly after the wake, Kenji receives a belated letter from Donkey, including a drawing of a strange yet familiar symbol and the question "Do you remember this symbol?" along with a request to get together some time.

The letter convinces Kenji that Donkey's suicide was, in fact, a murder. In his efforts to unravel the mystery behind his old friend's death, Kenji learns of a man known only as Friend who is the founder of a very popular cult. A cult that uses the symbol shown in Donkey's letter, a symbol that was in fact used by Kenji and his friends back when they were kids.

During their childhood, Kenji and his friends played a game in which they imagined the world being destroyed by a group of villains. Now, Kenji must gather his friends again, in order to prevent Friend, the man who took their symbol, from turning their childhood fantasies into a horrible reality.

Adapted into a [[LiveActionAdaptation live action film trilogy]] that is among the most expensive Japanese film projects in history. The films are very faithful to the manga (until the end, at least), which has inevitably led to criticism that they're impossible to follow if you haven't read it, due to time constraints forcing some important characters into smaller roles. Rather surprisingly, an AnimatedAdaptation of the series was never planned.

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!!This manga contains examples of the following tropes:

* AbandonedHospital: Kanna finds out some information about her mother in one. It isn't really a creepy one, though.
* AgentScully: As a child, Donkey firmly believes in science over superstition.
* TheAlcatraz: Umihotaru Prison.
* AmusementParkOfDoom: Friend Land. What happens there supposedly pales compared to [[{{Room 101}} Friend World]], but the audience never sees the latter.
* AntiAntichrist: [[spoiler: Kanna is Friend's daughter. The "Devil's Daughter".]]
* ApocalypseHow: Deconstructed and Reconstructed. At first, [[TheHero the heroes]] want to stop the BigBad from doing a class 3. [[spoiler: Turns out it was only a class 0, designed to frame the heroes for it and make the Big Bad more powerful. 15 years later, the Big Bad pulls out a real class 1, kills about 45% of humanity, and conquers the world. And 3 more years later, he tries to do a class X, only to be finally stopped by the main character. But it doesn't end here: after the Big Bad's death, one of his followers tries complete his master's plan, and do the class X, but is also stopped by the heroes.]]
* ApocalypticLog: Kanna finds [[spoiler: a note her mother wrote in an abandoned hospital, referring to her involvement in creating the virus: "I am Godzilla, I crushed 300,000 under my feet"]]
* BadassLongcoat: Otcho after TakingALevelInBadass.
* BadassPreacher: Several of the Catholic priests, such as Father Nitani, in the series used to be gang members and drug lords. They might work for Jesus now, but they can still hand you your ass.
** The Pope, when he was merely a priest, supported an entire bridge by himself, barehanded in a flooded river.
* BigBrotherIsWatching: Oh yes. Don't trust anyone, because they probably work for Friend.
* BigDamnHeroes: Several, but a notable one has Otcho [[spoiler: breaking through an overhead glass window at a church to protect Kanna from the policeman with the mole.]]
** [[spoiler:Sadakiyo]] of all people, pulls one of these right at the end by [[spoiler:putting a knife to Friend's throat and stopping him killing everyone at the expo grounds.]] [[spoiler:"I'm a good guy" indeed!]].
* BigNo: Kanna, when she finds out her tape player is broken [[spoiler: after also finding out that Friend is her father.]]
* BlandNameProduct: [[{{BBC}} BBV]] News.
* TheBlank: Friend occasionally appears as this after the mask is taken off. Justified as it's only [[spoiler: in a virtual reality program.]]
** A reveal showed that [[spoiler:Fukube began to see himself as one from time to time when he was a child]].
* BokeAndTsukkomiRoutine: Two of Friend's followers are a manzai comedy duo [[spoiler:who spread Friend's blood-hemorrhaging biological weapon to Osaka.]]
* BookEnds: The first and last chapter of the series both show the scene where Kenji puts "20th Century Boy" on the PA, although in the last chapter you see it from a different point of view.
** Not quite the last chapter, but at the start of the series, there's an enigmatic scene with a girl waking up and looking out her window and seeing a giant robot staring at her. In the penultimate chapter before 21st Century Boys, that scene is finally given context.
* BreakingTheFellowship: After the first major TimeSkip / WhamEpisode.
* CallBack: ''Loads'' of them throughout the series. For one thing the sheer amount of characters who're shown early in the series and make appearances in the last arc is staggering: it's clear Creator/NaokiUrasawa is not the kind of guy who simply forgets about even the smallest of characters and events.
* CallingTheOldManOut: [[spoiler: Kanna manages a pretty good one against Friend late in the series.]] Subverted in that [[spoiler: her father is dead by this point, and the man behind Friend's mask is an impostor.]]
* CardCarryingVillain: Moroboshi's killer. There's even a scene of him comparing himself to various old anime villains. He looks like [[Anime/Monster Johann]] and [[spoiler:as a high schooler wanted to have a WorthyOpponent in Kenji, who was "a good guy". It turns out that he felt hollow for everything else except killing Moroboshi]].
* CastOfSnowflakes
* CompressedAdaptation: The second and third films, due to their having to cover far more chapters of the manga than the first.
* {{Cult}}: Friend builds one up around himself that gradually grows in both size and intensity, up to the point [[spoiler: he pretty much takes over the world.]]
* DarkestHour: Chapter 169: [[spoiler:Friend is now hailed worldwide as a 'God', and has just released a new virus, killing several million people.]] It would be even more depressing were it not for the epic [[spoiler:HesBack]] moment in the next chapter.
* DeadlyEuphemism: Members of the Friend cult always say someone is "banished" ([[LostInTranslation the word in Japanese can also refer to when you stop being someone's friend]]).
** "Rejected" in the Viz translation.
* DeconReconSwitch: A pretty thorough one of pretty much every cliche from kids' comics.
** Friend himself is a thorough deconstruction of the EvilOverlord character archetype. [[spoiler:Flashbacks reveal the first man behind the mask believed himself a special person since childhood and, once shown up by his schoolmates, decided to prove them ''dead'' wrong. He does so at first by exploiting other people's need for a savior/messiah to make himself one, then frames the real heroes for his nefarious plans - the plague-spreading mecha - to take over Japan; and finally frames ''himself'' as a hero by "coming back from the dead" and "saving" the Pope, thus assuming enough power to become President of the world. And none of it would have happened had he not also used his underlings' desires and wishes to keep them loyal to him almost to the bitter end.]]
* DefectorFromDecadence: [[spoiler:Many major supporters of the first Friend decide to betray the second one and help the protagonists. Not so much because they realized that they're wrong but because they truly believed in the ''real'' Friend and not an ''impostor''.]]
* DisproportionateRetribution: At the very end of the series, we finally find out that the reason why [[spoiler:the impostor Friend]] was trying to destroy the world and it all started when [[spoiler:they were children, and Kenji stole a plastic toy badge from a local store and let him take the blame for it]].
** Don't forget [[spoiler: The first Friend.]] The reason that [[spoiler: he became Friend]] in the first place was to [[spoiler: get back at Kenji and his friends for showing him up when he was a child.]]
** Arguably, Friend was also a victim of this. [[spoiler: To have the rest of the kids in his neighbourhood treat him like a dead man, to the point that they can't remember that he didn't actually die, over stealing a cheap plastic toy? That's cold.]]
* DrivingQuestion: Friend's identity.
* DrugsAreBad: During her HeroicBSOD, Kanna is offered some "Love and Peace", only for flashback!Kenji for remind her that he didn't need drugs to be a great musician.
* EarnYourHappyEnding: And how! So much bad stuff happens not just to main characters in this, but to pretty much [[spoiler:the ''entire world'']] which makes [[spoiler:the final defeat of Friend all the more awesome.]]
* TheEndOfTheWorldAsWeKnowIt
* EnemyCivilWar: [[spoiler: After Friend is replaced, Manjoume starts planning a coup. After Friend publicly admits his atrocities, most of his army up and rebels.]]
* FauxSymbolism: An in-universe example is revealed with Otcho's explanation of [[spoiler:how he came up with the symbol that later became the Friend group's: he took the "continue on the next page" marker and drew an eye over it.]]
* FlashForward: [[spoiler: The first chapter has one with grown-up Kanna seeing Shikishima's new robot outside her apartment in 2018]], which doesn't happen until ''the penultimate chapter'', not counting the two volume epilogue.
* GoMadFromTheRevelation: The reaction to the bonus stage at [[AmusementParkOfDoom Friend Land]], specifically [[spoiler:the boy in the mask having ''a grown man's head.'']] [[spoiler:Kyoko only managed to see it and not kill herself because her memory was damaged from being removed and only gradually returned.]]
* GratuitousEnglish: Crops up a few times in the story itself but most notable in the pre-volume title pages. For example: [[spoiler:"Kyoko met Kenji of his boyhood, and saw something she should never seen ... it was the face of the "Friend"!! Who will survive the world of indistinguishable of friend and foe to the last!?"]]
* HaveYouToldAnyoneElse: Several times - characters confess their suspicions to a family member, friend, or authority figure, who inevitably turns out to be in league with Friend.
* HeroicSelfDeprecation: At first it's just regular SelfDeprecation for Yoshitsune, [[spoiler:but as time goes by and he reluctantly becomes leader of the heroes it turns into this.]]
* HesBack: [[spoiler: Kenji, and with about ten levels in {{Badass}} too.]]
* HopeSpot: The first two arcs are really two long Hope Spots.
* HowWeGotHere: The first chapter includes a scene during a UN summit in the 21st Century where several people are introduced as having saved humanity. Subverted in that [[spoiler:it happens twice during the course of the story, once about a third of the way through and once again towards the end.]] Also [[spoiler:since both times are similar it is hard to tell which one is the one being shown in the first chapter]].
* HumongousMecha: Subverted in chapter 41. In the slightly exaggerated words of one hostage robotics expert: "Robots do not work that way!"
** Nonetheless, his creation (an AwesomeButImpractical [[RealRobot Real Robot)]] plays a huge role throughout the story.
* IJustWantToBeSpecial: [[spoiler: This drove Fukubei to create the cult of Friend]].
* IronicNurseryTune: From the first time Kenji sees Friend in the video. You can hear it in all its glory in the [[http://www.youtube.com/watch?v=W18Kup-eqQA movie trailer.]]
* JigsawPuzzlePlot: When the story alternates between about three or four time periods, includes the liberal use of flashbacks and flashforwards, has a few timeskips, and is told in only rough chronological order, you know you've got one of these.
* KilledOffForReal: Plenty of people, including [[spoiler:Friend himself. [[DiscOneFinalBoss Halfway through the series]].]]
* TheLancer: For Otcho, both in his childhood and as an adult in the Kenji Faction.
* LaResistance: Kenji and his friends, later called the Kenji Faction.
* TheLawOfConservationOfDetail: Of all the people, places, and things in the series, Maruo's son is perhaps the ''only'' one that doesn't gain significance later on.
* LoadsAndLoadsOfCharacters: To give you an idea how many, the movie trilogy is estimated to include a cast of ''three hundred'' named characters...and that's probably less than half the original cast.
* LonersAreFreaks: Masao and Friend, both to extreme extents. Subverted with [[spoiler: Sadakiyo]] but just barely; [[spoiler: he's ultimately revealed to be on the good side but still a bit ill-adjusted and rather creepy]].
* LukeIAmYourFather: [[spoiler: Friend is one of Kenji's classmates]], and also [[spoiler:Kanna is Friend's daughter]].
* MisfitMobilizationMoment: When Kenji and his TrueCompanions prepare to try and [[spoiler:take down Friend's huge mech, which is currently smashing it's way through Tokyo]].
* MundaneMadeAwesome: Moving a mouse 5 pixels to left and pushing the left button has never been as awesome as in the second live action film.
* MusicForCourage: This happens pretty much every time [[spoiler:Kenji plays his]] song in the final arc. Every time it does happen is ''extremely'' awesome, though.
* MyDeathIsJustTheBeginning: [[spoiler:Friend had a successor lined up in the event of his death.]]
* NearVillainVictory
* NeverSuicide
* NoHuggingNoKissing: The closest that Kanna ever gets to a romance is blushing in [[spoiler:the last chapter]] while interacting with [[spoiler:Chouno]]. Likewise Kenji's relationship with Yukiji has never gone anywhere and despite [[spoiler:their communication at the end doesn't seem to be going anywhere yet, either]].
** To be fair, it's probably hard to think of romance with all the saving-the-world shit going on. Actually seems to be Urasawa's trait to not show romantic scenes on-screen.
* NoInfantileAmnesia: Averted as a constant plot point throughout the story is the cast's imperfect memories of their childhood. Though played straight and Justified in Kanna's case.
* NoNameGiven: Moroboshi's killer.
* NothingIsTheSameAnymore: After the series's first major TimeSkip, where [[spoiler: things are suddenly set 15 years later in a Japan ruled by Friend]]. See YourPrincessIsInAnotherCastle below.
* NotHisSled: The third film actually made a major selling point out of having a different ending from the manga.
* OlderAndWiser: Due to the large timeskips in the series, most of the original protagonists become this eventually. Otcho and a few others become this after the first timeskip, and the rest, ''especially'' [[spoiler:Kenji]] become this after the second. This usually comes hand in hand with them [[TookALevelInBadass taking a level in badass]].
* OnlyKnownByTheirNickname "God", [[spoiler: later revealed to have the name of Kaminaga Kyuutarou, aka "Kami-sama" (God).]]
** ''Friend'', for that matter.
* OptOut: [[spoiler:Keroyon]] doesn't show up at all for the Bloody New Years' Eve. Years later, he regrets this fact and Jumps at the Call when he stumbles onto leads to Kiriko.
* [[spoiler:OurHeroIsDead]]: [[spoiler:Throughout the entire middle part of the series]].
* PensieveFlashback: [[spoiler: The [[SimulationGame Bonus Stage]] is effectively one of these, though it's not IntangibleTimeTravel as people can interact with the people and objects, effecting things apparently until the program is "restarted".]]
* ThePowerOfRock: Plays a massive part in the final third of the series.
** 'GUUUTAALAAAAALAA SUUUUDAALAAALAAAAA!'
* PowerWalk: Kenji and co. do one in a manner most baddass when they head off to [[spoiler:take down Friend's mecha.]] In fact, the image of them [[spoiler: silhoutted against the robot's eyes]] is one of the most iconic ones in the series, leading to it being duplicated almost perfectly in the movie adaptation.
* PsychicPowers
* PsychopathicManchild: Many of Friend's followers come off as this. The scene where they're arguing over how to build their HumongousMecha [[spoiler: and then later when they're laughing hysterically and cracking jokes about the carnage it causes]] demonstrate it best.
** Friend himself shows shades of this as well. Enacting a doomsday scenario dreamt up by grade schoolers [[spoiler: to show up one of the kids who ''made'' said doomsday scenario]] certainly doesn't help his case.
* PunctuatedForEmphasis: "I ''said'', I'm singing a song. And when someone's singing a song, ''YOU. DON'T. SHOOT THEM.''"
** Also doubles as a CrowningMomentOfAwesome.
* PuttingTheBandBackTogether
* RagtagBunchOfMisfits
* RealityEnsues: The entire scene involving Shikishima and Friend's followers consisted mainly of the former explaining to the latter how the HumongousMecha seen in anime (when the group was arguing over building one in that style) could never possibly function in real life.
* RedemptionEqualsDeath: [[spoiler: Many characters trying to redeem themselves, especially the ones that once worked for Friend.]]
* RedOniBlueOni: Kyoko and [[spoiler:Kanna. One often acts on impulse rather than deliberation, partaking in the anti-Friend movement almost entirely by mistake. The latter can keep calm during very stressful situations and generally does not show much emotion unless someone makes her really upset.]]
* RefugeInAudacity: Friend basically uses this trope to take over the world.
* RetCon: After Friend dons the iconic "eye-symbol" mask, the old "hattori" mask is replaced with the new mask in flashbacks.
* TheReveal: Friend's identity, [[spoiler:the second Friend's identity]], what Donkey saw in the lab room, and plenty more.
* {{Room 101}}: Friend Land is halfway to this trope, and Friend World is all the way there.
* RousingSpeech: Yoshitsune attempts one in the second arc.
* ScareDare: ''School after dark.'' [[spoiler:It was just their classmates. And a boy they thought was dead and whom Donkey mistook for a ghost.]]
* SelfFulfillingProphecy: The only reason the events in the Book of Prophecy are happening is because Friend is ''making'' them happen.
* SequentialArtist: Quite a few characters.
* SimulationGame: [[spoiler: A painstakingly detailed representation of 1971, used inside Friend Land and can also be accessed from the Diet building. The heroes use it to find details from Friend's plans in the present and, sometimes, interact with their former children selves.]]
* ShaggyDogStory: [[spoiler: The first two story arcs, in which Friend ultimately realizes his plans despite Kenji/Kanna and pals' best efforts to foil them.]]
* ShoutOut:
** Yoshitsune said '[[Film/SevenSamurai seven of us is enough]]", but Kenji disagreed.
** [[Manga/AstroBoy Ochanomizu Engineering]].
** When Chouno and [[spoiler:Kenji]] meet Ichi The Spade, Ichi gives Chouno a disguise so he won't be recognizable: [[GalaxyExpress999 a ankle-length poncho]] [[CaptainHarlock and a wide-rimmed hat.]] [[spoiler:Kenji]] even lampshades it, saying "It's Three Nines."
** There's countless direct references to other classic manga: ''Manga/AstroBoy'', ''{{Phoenix}}'', ''Franchise/{{Gundam}}'', ''[[{{Gigantor}} Tetsujin 28]]'', and ''Super Jetter''.
*** When [[spoiler:Kenji comes back]], he temporarily uses the nickname of [[AshitaNoJoe Yabuki Joe.]]
** There's even some Series/{{Thunderbirds}} toys in [[spoiler:the 'Friend Museum']].
** The title itself! "20th Century Boy" is a song by [[Music/MarcBolan T. Rex]], which has been covered by [[Music/XJapan at least one very iconic Japanese rock band]].
** The crossdressing prostitutes comment that Chouno's dancing looks more like judo, a reference to Urasawa's previous work ''Manga/YawaraAFashionableJudoGirl'', where the protagonist's judo was said to look more like dancing.
** The holographic BlandNameProduct version of ''Franchise/StreetFighter''.
* ShutUpHannibal: [[spoiler:Kenji]] does an epic one of these to [[spoiler:Moroboshi's killer]] late in the story, where he calmly makes him completely breakdown when he exposes his CardCarryingVillain persona as being merely a facade. What makes it more epic is the fact that he's facing down the barrel of a gun the whole time he does it.
* SquareCubeLaw: Specifically mentioned by Shikishima as the reason Friend's HumongousMecha can't work the way he desires it to. [[spoiler:Then ignored as Shikishima went on to actually create a working version of the robot years later.]]
* StepfordSmiler: Near the end of the manga, it's revealed that many of the Friends have pretty much turned into this, having to keep a sunny disposition at all times for fear of [[DeadlyEuphemism rejection.]]
* StormingTheCastle: Happens three times in the final arc: firstly when [[spoiler:Kenji]] and co storm the 'castle' of [[spoiler:Moroboshi's killer]] and twice when the resistance storm Friend's tower. The second time is much easier for them seeing as how [[spoiler:all the guards have lost their morale.]]
* StylisticSuck: Kenji ''really'' doesn't enjoy the 169th Friends Concert, even apart from the need to keep an eye out for the BigBad.
** AI ROCK YUU!!!
* SuperFunHappyThingOfDoom
* SuperWindowJump: Otcho does a great one (through a stained glass window, no less) when he tries to save [[spoiler: Kanna from being assassinated]]
* TakingTheBullet: [[spoiler:Friend does this to save the Pope, making his "resurrection" all the more dramatic.]]
[[spoiler:* TakingYouWithMe: Maruo comes very, very close to doing this with Friend and a bomb. But remembering Kenji's words about not hurting innocents convinces him not go through at the very last minute.]]
* TitleDrop: [[spoiler:The second Friend drops it as a hint of his identity]].
** Plus the title is based off of the T-Rex song "20th Century Boy", which is played a couple of times over the course of the manga. And it is, as the final reveal shows us, ''very'' important to the plot.
* TookALevelInBadass: Most of the protagonists, with Yoshitsune being perhaps the most striking example.
** Don't you mean [[spoiler: Kenji]]?
*** Don't forget Kanna. [[spoiler:From taking her first steps to walking into the crossfire of a gang war.]]
** Otcho too. From salaryman to [[spoiler:freelance ninja]] in a couple of years.
* TokyoIsTheCenterOfTheUniverse: Young Kenji and his friends write a story about supervillains conquering the world. "So what's gonna get hit first?" "Tokyo?" "That's last. The important stuff has to happen in Japan, so if they start here, it'll be all over already." Much later, the story starts coming true.
* TrueCompanions: There's only one reason for full-grown level-headed adults to literally ''put their lives aside'' and travel back to their hometown, from as far away as Germany in one case, just because of one cryptic note saying 'let's take this symbol back.' In Otcho's case, knowing it was Kenji did it for him.)
* TwinBanter: Yanbo and Mabo.
* UnEntendre: A CrowningMomentOfFunny involving [[spoiler:Yukiji talking about her drug-sniffing dog. "And then he stuffs his nose into my..."]]
* [[spoiler:VillainWorld]]: After the first arc. [[FromBadToWorse Gets much worse]] after the second.
* TheUnreveal: About a dozen characters get to see Friend's real face before the readers ever do.
** [[spoiler: Neither the readers nor the characters ever see the second Friend's real face at all. They find out his name, though.]]
* UnusuallyUninterestingSight: Nobody really seems to care all that much about gas mask-wearing businessmen carrying suspicious briefcases, especially [[spoiler: in the middle of a worldwide outbreak of a mysterious deadly virus.]]
* VirtualGhost: [[spoiler: Manjoume]] in the epilogue.
* WeAreEverywhere
* WhamEpisode: There are quite a few throughout the series. Most notably is when [[spoiler:Friend is both killed and unmasked, halfway through the series]]. The chapters surrounding [[spoiler:the 2015 World Expo]] and [[spoiler:Kenji's return]] also qualify.
** The final twenty or so chapters are just full of nonstop wham. To be expected with the GrandFinale, really.
** The Kenji Faction marches off to the big climactic showdown with Friend. Cue [[spoiler: a 15 year TimeSkip. Friend won, and now rules the world while Kenji and friends are regarded as history's greatest villains.]]
* WhatHappenedToTheMouse: The series's [[LoadsAndLoadsOfCharacters "no name wasted" policy]] made the fact that [[spoiler: Maruo's son]] never came back from [[PutOnABus his bus ride]] quite bewildering...or sad...really sad.
* WhereItAllBegan
* WrittenByTheWinners: [[spoiler: One of Friend's favorite tactics. It pays to be a VillainWithGoodPublicity when the world believes ''you'' saved the world from those RagtagBunchOfMisfits.]]
* XMeetsY: ''Literature/TheStand'' meets ''Literature/{{It}}'' with a dash of ''LeftBehind'', minus the religious/spiritual elements.
** Or the twisty-turny, flashback focused MythArc nature of ''Series/{{Lost}}'' meets the child-hood reminiscence of ''Film/StandByMe''.
* YouCantThwartStageOne
* YourPrincessIsInAnotherCastle: It initially seems like the series is going to end when [[spoiler:the heroes try to stop Friend from destroying Tokyo on Bloody New Year's Eve with a giant robot]]. However, as you can probably tell from the chapter count, that it is most definitely ''not'' the end. It turns out that [[spoiler: Friend was just using the (fake) robot so that he could destroy it himself and play the part of the hero, whilst framing Kenji and his friends for all the chaos and destruction.]] Suddenly, [[spoiler:the story jumps forward 15 years and Friend is now head of an opressive Japan, and all our heroes are either scattered, in prison, or presumed dead.]] OhCrap.
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