Chekhov's Gun/Anime and Manga

"My daddy used to tell me a bedtime story that when Pokemon are sad, and they cry...their tears are filled with life."
 * In the end of the Trigun anime, where
 * In season 2 of Natsume Yuujinchou our titular Hero finds an ayakashi in his house, but he doesn't get rid of it because he finds out that it's harmless and can even prevent disasters from happening.  At the very end of the episode, he collects the   saying that they're very precious to him.
 * In the Axis Powers Hetalia movie, In the beginning of the movie, Italy is seen scribbling funny faces on the photos of The Faceless aliens. It turns out to be the key to defeating them.
 * Ouran High School Host Club hangs a lampshade on this. The device that sets up the plot of the whole series is a large, expensive vase that will be broken. The vase is seen in the foreground of most of the shots leading up to the breakage...and is indicated by a large, blinking arrow. The blinking arrow returns in later episodes to point in every device and person whom will set the plot of the episode.
 * The First's Necklace that Tsunade gives Naruto becomes very important after the timeskip...
 * During the Chunin exams the hole in the arena Naruto had to create to beat Neji turns out to be very important for the success of Shikamaru in his match.
 * Shortly before the first round of the Chunnin exams, Rock Lee challenges Sasuke to a one on one fight. That later becomes important for Sasuke during the preliminary third round.
 * When Sasuke's Team Taka is fighting Killer Bee, there's a rather conspicuous focus on . A couple chapters later and.
 * The new book Kakashi had becomes very important in the Pain arc.
 * That book itself was a gift to Kakashi from Naruto, and Naruto makes good use of it during Kakashi's bell test.
 * One of Jiraya's books about a battle against a rogue ninja. Once again is important in the Pain arc.
 * Itachi stuffed a crow down Naruto's throat. About 150 chapters later, it comes out again and turns out to be.
 * Pain mentions that . About 30 chapters later, it turns out this was not hyperbole. Later it's shown how he found enough material to create.
 * Naruto's ability to is later shown to be a standard weapon of jinchuuriki. And the final attack he used is shown to be.
 * Wendy Garret in Gun X Sword carries around a gun given to her by her brother, Michael, when their home was attacked. It only has one bullet. There may as well be a large tag on the handle saying "FUTURE PLOT DEVICE".
 * In Yu-Gi-Oh!!, if a character even explicitly obtains a given card (from a trade, a victory, or even just though picking it) rather than having it in their deck, it will be absolutely critical to their victory in at least one duel that season.
 * In episode 139 of the first series, Yami draws a card and places it on the field without looking at it, and Ishizu says that Yami knows the card is Fiend's Sanctuary. Yami's ability to predict and pull exactly the card he needs goes unnoticed until a hundred episodes later, when it's revealed how it exactly works.
 * Joey's Time Wizard! He's saved their necks with that card a lot so far...and I've only watched the first season!
 * The Deck Masters (Except for Joey's against the duel with Johnson) and some of the cards that Yugi and their friends (Specifically Serenity) during the Virtual World Arc.
 * Kuriboh actually helps save Yami Yugi from defeat, then, because of a card Rainbow Blessing, allows Yami Yugi to strike Gansley directly and win the duel.
 * The Dark Magician Girl helps Tea against by allowing her to summon Yugi's Dark Magician out of nowhere.
 * With Serenity, somebody who has never dueled before, she picks a card (St. Joan) thinking it looks cool. Combined that with her Deck Master's ability and with some help from Duke Devlin, her monster obliterates Nesbitt.
 * Kaiba's Lord of Dragon allowed him to summon a Blue Eyes White Dragon and obliterate Lector.
 * In Yu-Gi-Oh! 5D's, the final Signer Dragon, Life Stream Dragon, originally appeared in one of Luna's dreams. It was finally unlocked by Leo from Power Tool Dragon late in the series.
 * Early in the second season of Ghost in the Shell: Stand Alone Complex Togusa investigates the disappearance of a man who was last seen talking to people who have hired a number illegal immigrants as cheap laborers. It turns out he died in an accident while salvaging parts from an old nuclear power plant inside a restricted area. However, it's not a single episode about exploitation of refugees and endangering workers to save money, but kicks off the seasons main plot as.
 * In Mahou Sensei Negima, Ayase Yue's Orbis Sensualium Pictus and Saotome Haruna's Imperium Graphices were both created well before they became useful. Both Pactio artifacts were the main way for the Ala Alba (not named that yet) to escape and defeat enemies during the arc. Nodoka's Diarium Ejus isn't as distant a creation to use timeline.
 * A better example of a Chekhov's Gun in Negima is the bracelet that Ako won when she and Negi (disguised as Nagi) finished second in a pageant-like event during the school festival. Over a 150 chapters later, Ako is seen wearing the bracelet, with the item plying a key role in
 * Spoileriffic example: Note Ku Fei's comment in panel five, then read chapter 311.
 * Way back in chapter 162, Chao brought her secret item, "Chao's family tree" that would indicate who will Negi marry in the future. It pops up again in chapter 349 (a copy of it at least) and this time, Negi's descendants are now a blank slate which means everyone gets a chance at being Negi's partner.
 * One Piece is fond of this, though how critical the Chekhov's gun is varies per use. Among examples are a rather odd pinwheel worn in the hat of Genzo, the sheriff of Nami's home village. This pinwheel has three Chekhovs to its name. First, it inspires the attack Luffy uses to remove the villain-of-the-arc's giant sea cow from the fight. But the true Chekhov comes at the end, when a flashback reveals that Genzo put the pinwheel in his hat to make the then-baby Nami laugh. To everyone's surprise, it worked, and so Genzo continued to wear it as a way of supporting Nami as she struggled, removing it only when Nami left with the Straw Hats. Third, along with Bellemere's tangerines, it forms the basis for Nami's new tattoo.
 * The concept of Haki is a good example of this. In the very first chapter, Shanks is seen scaring a Sea King away simply by gazing at it. More than four hundred chapters later, the power is named but is not elaborated upon. Luffy is later seen unknowingly using a similar gaze on Duval's Bull, and it isn't until five hundred chapters in that the concept of Haki is fully explored.
 * In the Davy Back Fight arc, Luffy is outfitted with an afro, thinking that it will make him stronger in his upcoming fight. Then, at the end of the fight, a shard of mirror caught in the afro proves crucial to his victory.
 * Luffy's brother gives him a piece of blank paper early on in the Arabasta arc. The paper's purpose is left unknown for several hundred chapters/episodes (depending on whether you follow the manga or anime.)
 * The third movie has Usopp use an actual boomerang in order to attack the Big Bad, but as it turns out, it was fairly useless. However, it's later used to lure a bunch of Horn Eaters belonging to the big bad, by imitating a pair of horns, into a ravine, where they are trapped.
 * Oda seems especially fond of this trope. Early on in the story, our beloved pirate/clown Captain Buggy is looking for the treasure of one Captain John. A long long long way down the line during the Thriller Bark arc, Captain John's zombie turns up. After the conclusion of this arc, Buggy's self-proclaimed rival Luffy finds a cool armlet in the Thriller Bark treasure hoard, which stays with him for about forty chapters before he and Buggy end up in Impel Down together. Only THEN, do we realize that the armlet Luffy took is in fact the key to finding the long lost treasure that Buggy has been looking for all along!
 * One word: Laboon. The crew meets him just after they've entered the Grand Line, and it is mentioned that Laboon is waiting there for a pirate crew he befriended to come back. Several hundred chapters/episodes later, they gain a new crew member (Brook) who just happens to be the only remaining member of that pirate crew and his goal is to keep his promise that he'll come back to see Laboon again.
 * Captain John's treasure was predicted right after the chapter he picks it up at was released, so it wasn't a huge shock. Still the Captain John plotline is relatively low-key, but is probably another set up. When it was first shown it was just thought to be a random thing to let us check in on Buggy, and the real important event was Ace showing up on his ship. No doubt Oda is the king of this trope. Laboon and Crocus in particular have a lot of events connected to them. It seems everything after they arrive in the Grand Line has had some kind of purpose later on. The sheer impressiveness comes when you realize that some of these set-ups took more than a decade to complete.
 * Early on, we can see that some of the Arlong Pirates seem to have a second, sun tattoo in addition to the one that identifies them as part of the crew. Hundreds of chapters/episodes later one, it's revealed that this links to another, legendary pirate crew, the Sunny Pirates formed by Fisher Tiger from freed Fishman slaves with the aforementioned sun tattoo (actually a brand) being their symbol as well as a way to cover up the brand they received as slaves. The whole slavery angle ties in to the whole Fishman/Human racism dynamic that underpins the Fishman Island arc.
 * In the first part of the Ecchi OVA Labyrinth Of Flames, we briefly catch a glimpse of a Soviet T-34 tank during maintenance. Its reappearance towards the end of the second episode (powered up by Kalinka, no less) doubles as the resident Lovable Sex Maniac's Crowning Moment of Awesome.
 * In Blade of the Phantom Master, the main character attacks a gun dealer about half-way through the movie after he is shown a little gun designed for hiding in a sleeve, which he keeps after he tosses the gun dealer into the sea. Guess what the penultimate blow to the bad guy uses.
 * Pokémon Special gets away with this more often than is healthy for the reader's mind. Lt. Surge's gloves, the feathers on Yellow's hat, a shard of the Grand Meteor (multiple times), and the list goes on. Almost every object explicitly discussed in dialogue returns later in the saga -- or even in a completely separate saga -- to turn the plot around.
 * The anime gets away with this a few times too, the most prominent being in "Pika and Goliath" -- Ash revealed he kept the Thunderstone he got all the way back in "Electric Shock Showdown" in case Pikachu changed its mind about evolving.
 * In the well-known deleted scene to the first movie, known as "The Birth of Mewtwo", we've got a serious Chekhovs Gun. Amber reveals that Pokemon tears are full of life, and though it seems unimportant at the time, it becomes very significant when  "The Birth of Mewtwo" was cut from the English version, making   completely ridiculous...


 * Actually, even the Dub includes a very subtle Chekhov's Gun for : When Officer Jenny explains the boat trip to New Island was cancelled due to the storm, the woman accompanying her addressed that cave paintings explained that several pokemon died in a storm, and that the survivors tears revived them.
 * In the same movie, when Brock sees the missing Nurse Joy poster, after remarking that she's cute, he realizes that he recognizes her. It's later revealed that she was in fact the one who summoned them to New Island in the first place, under Mewtwo's orders.
 * In Tsubasa Reservoir Chronicle, the eponymous reservoir, while it appears halfway through the story, does not seem relevant until the final arc, where a flashback and a reveal make it retroactively the most important location in quite possibly the entire CLAMP multiverse. Shoulda known CLAMP wasn't just throwing in random words.
 * Gankutsuou has many. One is a gun placed in a desk drawer by Fernand. The two suits of armor outside the Morcerf mansion are actually giant mecha. Then there's the watch given to Albert by The Count when they first met.
 * Stock in trade for Eat Man, where Bolt Crank may spend the entire adventure snacking on a bag full of bolts and other small machine parts. At the climax however, he'll swallow the last bolt, then whip a BFG he'd just finished eating the last of.
 * Really, if he eats something at any point in the story, you can expect him to use it later, even if he obviously didn't plan to. For example, in one chapter, he escapes from being locked in a safe by eating the safe. Later,.
 * There's also a subversion, during the MOLE arc. Early on, Macus is playing with a yo-yo and musing on how, in Zero-G, the yo-yo goes all the way to the end of its string regardless of what direction it's thrown. Bolt promptly eats it..
 * Clannad: Remember those orbs of light Miyazawa and the Girl in the Illusionary World were talking about? Those'll really come in handy much later.
 * A few times in Ranma 1/2: the horned mongoose whistle Shinnosuke gave Akane ten years ago turns out to be the key to pacifying and sealing the Orochi of Ryugenzawa. The photo of Akane that Nabiki snapped (and tried to sell to Ranma, but was bought by Ryouga) gave him the impetus to save himself from a rockslide, and was later used by the bad guys to kidnap her.
 * In Macross Frontier, Sheryl loses one of her earrings (inherited from her mother) when Alto crashes into her in mid-performance. She goes nuts looking for it, but later tells him to keep it as a good luck charm during combat (at which point it's lost forever.) It is later revealed that the earrings are made of . It became so important, the Blu-Ray release of Macross Zero went back and added the earrings in a scene with Sheryl's ancestors.
 * Macross Frontier gets points for sneaking Chekhov's Gun into what looks to be a throw-away Accidental Pervert gag.
 * In Sailor Moon, when Mako/Sailor Jupiter is introduced in the first season of the anime her rose-shaped earrings sparkle with reflected light. They seem insignificant until the beginning of the fifth season, when
 * Eureka 7 features a very sneaky Chekhov's Gun in the form of Eureka and Anemone's collars. They seem like random accessories until the very last episode, where it's revealed that they're
 * Kinda foreshadows its significance in episode 11 when Eureka does not take the collar off when bathing and episode 19 when the collar was intact while Eureka's clothes and hair were being consumed by the Scab Coral.
 * In Utawarerumono, Eruru wears an odd, apparently decorative loop in her hair at almost all times. Later it is revealed that
 * Ichigo's Super Hollow form in Bleach could be this. They hint several times that the longer he stays in Hueco Mundo, the more power his hollow side absorbs.
 * Also if you consider that his previous hollow form was more Adjuchas looking and the super was more Vasto looking, it makes sense on the power scale...somewhat. As well, a little actual planning on Kubo's part when he makes sure to note that Ichigo's hollow tells him that he can't always expect to be the "king" because it's not just Ichigo that's getting stronger.
 * Also, the  Hanataro briefly brings it up before the subject is dropped. It is only brought up again with its meaning when.
 * Also, Chad himself mentions while in Hueco Mundo that his power . This is also ignored until.
 * Magical Girl Lyrical Nanoha has Chekhov's Wave Motion Gun; an early episode in A's gives us an apparently throw-away scene involving a high-powered magical cannon, the Arc-En-Ciel. The Arthra is out of service most of the season being refitted. When it returns, what should it come equipped with, but an Arc-En-Ciel.
 * Oh please. There's another one which is WAAAAAAAAY back in season 1: Wide Area Search. Simple spell just to collect the magical jewel shards right?
 * In conjunction with the above spoiler, Season 3 (StrikerS) opens with Nanoha rescuing a girl from a raging fire and using Divine Buster to blow a hole clear through the entire building to get her out. That scene is nothing but Chekhov's Guns. The girl becomes Subaru, whose origins are crucial to the plot and lead you to one of the big Wham Moments of the season; and Nanoha
 * In Monster a hospital director helps himself to the unconscious antagonist's candy. Nothing happens for a while. And then they find his body next to a candy wrapper.
 * Detective Conan: It's frequently used and a regular watcher ends up being trained to look for them in every episode. They're particularly subtle, too. One episode involved the culprit wearing a headband with the name of her favorite singer. The singer, Okino Yoko, has an accent over the third 'o' . When the culprit committed the crime, blood, which was the same color as headband, got on it (conveniently right on the accent mark), and was discovered by Mouri *cough* Conan *cough* as the killer. If you are an American viewer, you might tilt your head at the odd spelling at first since, hey! You don't know how Japanese worth squat! It was probably caught easier by Japanese viewers, but still subtle, and no one really pays attention to it until Conan provides the proof.
 * In the Vampire Princess Miyu TV series, Miyu and Chisato purchase two good-luck charms from an artisan.
 * In the Lupin III movie The Castleof Cagliostro, there are a few details you might miss the first few times you watch the movie:
 * Right before Lupin and Jigen are attacked in their room by the Count's assassins, you see Lupin fiddling around with some sort of forgery kit. What's he doing, you ask?
 * Near the end of the film, as the archbishop sent to marry Clarisse and the Count travels to Cagliostro, you might notice
 * In the first movie, Secret of Mamo.
 * Griffith's Crimson Behelit in the Berserk anime. We first see it after the naked water fight that he and Guts have in an early episode, and apart from a different colored Behelit taken off a demon Guts kills in the very first episode, it doesn't have a lot of significance, save for Zodd's prophetic warning about how when Griffith's dream crumbles, Guts will face his death. The Crimson Behelit turns out to be
 * Transformers Robots in Disguise had a particularly impressive example. When the Decepticons were introduced, Scourge's protoform scanned a truck that Kelly was trying to escape in, and which Optimus Prime was holding up, meaning he simultaneously scanned Prime. Initially, the only outcome of this seemed to be a Decepticon who was ironically similar in appearance to the Autobot leader. Much later, it turned out that this event had given Scourge a hybrid Predacon/Autobot/human spark based on that of Optimus Prime, which in turn allowed him to control Fortress Maximus.
 * In Wind A Breath Of Heart, everybody has a special power. Except the protagonist. This point is made whenever the subject of the powers comes up, suggesting that the protagonist will eventually awaken to a kickass power. Oddly enough, the episode in which he uses his power was taken out of the TV broadcast.
 * In Mazinkaiser episode six, Boss gives Kouji a bar to protect him while trying to get to Mazinkaiser. Kouji accepts it, but points out he has protection in the form of his Photon Gun. In the next (and final episode), Mazinkaiser's steering wheel is destroyed in battle with Hell King Gorgon. As the machine tumbles back, the bar tumbles out and Kouji remembers Boss giving it to him, causing him to shove it in the shaft and finish the fight.
 * The sequel movie, Deathmatch! Great General of Darkness has an interesting one, though - way back in Mazinkaiser episode one, the titular mech thrashes an altered Mazinger-Z and it is never seen in the series again and it is never mentioned as to its fate. Come the movie, a knife Kouji uses to defend himself is revealed to be made from Mazinger-Z's remains!
 * The bottomless swamp in Fate Kaleid Liner Prisma Ilya which Rin and Luvia fell into.
 * Shakugan no Shana has a Chekhov's BFS, Blutsauger. It first appears in the hands of a minor antagonist, and when he's defeated, leaving the sword, any Genre Savvy person could correctly deduce that by the end of the season, it will be in Yuji's hands. Although it trades hands several times, Yuji does indeed use it in the first season finale, and in the second half of the second season he carries it regularly.
 * There was also the antifire ring, which shows up with the first minor antagonist and is given to Yuji afterwards. He uses it to survive two later fights, including the finale of the first season.
 * The tiny bombs that Sagara Sanosuke got from Tsukioka Tsunan in Rurouni Kenshin play an important role in the Kyoto Arc when Sagara uses them to blow up Shishio's battleship, earning a major victory for Kenshin and company.
 * Miaka Yuki's unborn child in the 3rd Fushigi Yuugi OVA. The only Shinazho that wasn't a MacGuffin.
 * Daisuke Aurora's silver-bullet pendant in Heat Guy J
 * Zoids Chaotic Century has a pretty big one. Remember The Valley of The Rareherts? It turns out that
 * Where to begin with Mai-HiME? Seriously, this series has great rewatch value.
 * First shown in Episode 2, Crowning Moment of Funny in Finale.
 * my Mom, somehow, picked up on it in their  first onscreen interaction, the first time she watched the series in Episode 3, becomes important in Episode 21.
 * in Episode 5. See Episode 17. Because they were right about everything.
 * Makes its first appearance in Episode 6, becomes a vital clue for the audience in Episode 18.
 * Revolutionary Girl Utena is mostly just clever storytelling and repetition so it's actual ChekhovsGuns are much harder to spot. Akio's planetarian is one of them, but a much more significant one is the Sword of Dios, drawn from Anthy's bosom every other episode. No one asks why. Come the second arc onwards.
 * There's actually a fairly elaborate one in Tantei Opera Milky Holmes at the end of season 1. Mary and Kate from episode 5 inspire Milky Homes to not give up. Aileen from episode 4 gives the girls transportation to their final battle, the recurring Pig-Faced character comes by to deliver a Toys-Powered Ring from Sonya (episode 9) and a wedding plate from Claris (episode 6), Sherlock's various encounters with Henriette's Cleavage also come into play as well.
 * The mangaka of Aoi Hana and Wandering Son frequently includes characters that looks like they'll only appear once or twice, or that don't have much to them, that become important characters later on. Same thing with plot devices.
 * Chekhov's Breasts
 * THE iDOLM@STER - Haruka's present for the Producer, a wallet.
 * In Spirited Away, the gift that Chihiro received from  was able to cure Haku from his injuries and free Noh Face from all the food (and people) he had eaten.
 * In Saint Beast, an angel helping Shin move drops a stack of his books, and the first one Shin picks up is about witchcraft transformation. The Monster of the Week? An evil tree that's actually an angel who underwent witchcraft transformation. Overlaps with Someday This Will Come in Handy.
 * FLCL episode "Brittle Bullet". Ninamori receives a water pistol during the episode. At the end she uses it to cool off Naota after he's ejected from Conti.
 * Early in Princess Mononoke Eboshi warns that a wolf's head still has the power to bite, even after being severed. Guess how she loses an arm later?
 * Inverted in Yokohama Kaidashi Kikou -- the story introduces tons of "unnecessary elements," never using them. This includes characters that are introduced but never meet each other, offers that are never used, and an actual gun that is never seen again after its introduction.