The trailer for the fourth Naruto overall movie seems to strongly have this going. For those interested, the tagline is "Naruto Dies". This turns out to be true, but it's a really weird situation. Naruto is bodyguarding a priestess who has the power to see her own death and usually puts someone else in that place so she can survive. So there is a continuity where Naruto dies in fact this happens in the beginning of the movie, but it's not the main one.
Regular Naruto episodes do this from time to time, too -- early in Shippuuden, one episode made Naruto's knowledge of the ending of an "Icha Icha" book a plot point. The "On the Next..." consisted of Tsunade yelling at him for reading porn, and telling him he'd be cleaning the Academy's toilets as punishment. The actual next episode was the start of the Rescue Gaara arc.
It was more or less intentional, since the first few chapters of Shippudden all do that. There was another where Naruto and Sakura argue over why they got a D rank mission.
Much earlier, the trailer and title for one episode suggested the seal on the nine-tailed fox was about to be broken... but it was only loosened when Naruto began using its chakra for the first time, and we eventually find out that's only like one-tenth broken.
In the Three-Tails arc trailer, Naruto stands beside the other members of Team 7 and Team 8 on the foggy lake, apparently facing off against Deidara and Tobi, and Orochimaru and Kabuto. He says "I'll never let them take the Three Tails!" The Akatsuki don't come for the beast until after the Leaf ninja have left, and Naruto doesn't meet Tobi until late in the next arc, so this scene never happens, and he never says that line.
Cartoon Network's advertisements for Tenchi Muyo! were infamous in this regard. Thanks to the Toonami-style editing that the trailers underwent, Tenchi Muyo! was made to appear as an exciting, action-oriented anime full of guns and stuff. While the show does have some action sequences, it is certainly not action-oriented in any way, and the disappointment was reflected in the show's ratings. Note also that the trailers combined clips from all three of the series' incarnations (Toonami showed all three series' one after the other).
This might be a double example, as the trailer for the show also played up the show's steamier side (complete with an out-of-context clip of Sasami saying "You're a naughty boy, aren't you, Tenchi?") While the uncut show does have quite a bit of this, the version broadcast on Toonami cut out any and all sexual references.
Similarly, a TV-guide description of Tenchi Muyo! in Love was "Police officers chase an escaped convict." While technically true, this leaves out the fact that they're Space Police officers, that the convict is a evil alien, that they're chasing it back in time, and that said officers are only two members of the group that goes back -- and the ones who get the least attention, at that.
The trailer for the original Hellsing TV Series not only has almost nothing to do with the plot of the TV series, but also features a completely different style of music and higher quality/differently styled animation to that which occurs in the series. The problem is that the trailer is based mainly off a volume of the manga that never made it into the TV series.
It also ends with a tease of the Major. Neither he or anything to do with Millennium end up in the series, as it Overtook the Mangajust before the introduction of Millennium.
Sailor Moon was marketed by the dub company to US TV stations with this tape, informing potential business partners that "Boys will love the non-stop action!"
The back of some of the DVD boxes for Gravitation are very carefully worded in just how they summarize the series and its events. It's entirely possible for someone to pick it up without realizing that it's a Boys Love series.
Planetes does this deliberately with its Post Episode Trailer. While they use clips from the next episode, all of them are stripped of context and out-of-order, making it completely impossible to accurately guess the next episode's contents.
Inuyasha is also known for misleading Post Episode Trailers. While the narration is usually fairly accurate, it's played over mostly random shots from the next episode, and is done by the characters themselves who have a tendency to exaggerate and/or go off topic. One notable instance includes 2 or 3 references to Jaken, Sesshomaru's minion who featured prominently in the next episode, but those references are drowned out by Kagome confusing his name for Jan-Ken-Pon, the Japanese name for Rock-Paper-Scissors, and trying to convince the others to let her teach them how to play it.
Mai-HiME also has some very misleading Post Episode Trailers. Most notably, after episode 15's cliffhander ending leaving us in doubt as to whether Mai is dead, the trailer indicates that she is, which turns out to be untrue.
For every Pokémon movie, the early Japanese teasers and trailers contain scenes not in the released film. The most noted one, a silhouette of Mewtwo in the first trailer of the third movie, given that Mewtwo already had a focal movie, the first one. Naturally, Mewtwo did not appear in the final film.
I would say the most notable, and odd, was the first movie's trailer. What does an adult Misty with her GSC hair style, that police lady, and a girl who looks like Misty's future daughter, have to do with Mewtwo?
It's speculated that around the time this trailer was made, the Pokémon anime was slated to end at episode 78, with the movie (which would most likely be told as a flashback by an older Misty) serving as the "finale" to the show.
That still doesn't explain why Miranda was with Misty though.
Some of the trailers for the eighth Pokémon movie (Lucario and the Mystery of Mew or Mew and the Wave-Guiding Hero, Lucario depict scenes like Kid's van being caught in the middle of a geyser field, Lucario dodging falling rocks, Lucario apparently dead of unknown causes, and various other scenes, none of which are seen in either the Japanese or English versions of the film.
Not to mention how a trailer for Destiny Deoxys depicted a badass space battle between Deoxys and Ash riding on the back of Rayquaza, which was nowhere to be seen in the final cut.
Many old promos for English version episodes when the series was dubbed by 4Kids did this as well. One in particular showed Ash being transformed into a Pikachu, which led many to believe that was the main focus of the episode. Turns out that it didn't happen until the end of the episode and the transformation was undone immediately at the beginning of the following episode. Needless to say, many fans were greatly disappointed.
The trailer for "Zoroark: Master of Illusions" first depicted an aerial battle between Lugia and Ho-Oh, possibly intended to be a Heart Gold / Soul Silver tie-in, later cut. The recent trailer shows Zoroark transforming into an evil version of Ash, but while Zorua did transform into Ash in the final film, it was for fun and had no real effect on the plot.
The Gakuen Utopia Manabi Straight!! trailer featured missiles destroying clocktowers and city-levelling explosions, absolutely none of which were featured in the show itself. This somewhat disappointed many viewers, who were hoping for a Twist Ending they had pre-emptively dubbed "The Lolicaust".
Wagaya no Oinari-sama. plays its next episode previews completely straight at first, but as the series goes on, the previews start to consist entirely of scenes that never happen in the next episode. Such as a Kaiju battle between Kuugen and Byakki.
Spoofed by Excel Saga by having trailers which have the scenes edited so the show resembles a romantic comedy and an action show.
Quite a lot of Neon Genesis EvangelionPost Episode Trailers had Misato Katsuragi promising "more fanservice!" in a cheery voice. Not many episodes delivered, or at least not as much as was promised. One trailer promised that the series was a light-hearted mecha anime.
The preview of the second movie played at the end of the first turned out to have several scenes that didn't actually appear or did appear, but were radically different. This is due to the fact that the second movie was still just beginning production when the preview was called to be made. Also, the end-of-movie previews are a Mythology Gag for the Post Episode Trailers of the original series, including the promise of more fanservice.
Rebuild finally paid up that fanservice Misato's been promising.
Spoofed in the fan-made flick, AMV Hell. At the end of the first AMV Hell, there is a trailer for AMV Hell 2, with several scenes set to epic music, with the note "Featuring none of the scenes shown here." Nothing is sacred, indeed.
Clannad's anime adaptation does this quite a lot with their Post Episode Trailer every episode. One implied a pretty explicit Ho Yay relationship that might form between the main character and his closest friend, followed by his friend's father commenting that the relationship "looks like fun."
Another particularly hilarious one is Nagisa seemingly agreeing that she's a bully.
Behold the trailer for Tweeny Witches (Maho Shoujo Tai Arusu). Look exciting? Not a single frame of it appears anywhere in the actual series.
The trailers for the anime adaptation of one Tear Jerker of a strip in Axis Powers Hetalia showed the episode being in English (the strip concerns America and England, both being English speakers). Fans feared some very serious Narm since the Engrish was barely understandable. However, the actual episode turned out to be in Japanese.
Mazinger Z used extreme hyperbole in its next-episode previews, and was not above outright lying to the audience to hype up an episode. The most famous example is an episode called "Koji Kabuto Dies in Lava!"
This one is so infamous it was endlessly mocked and parodied, culminating in one of the Mazinkaizer stage in Super Robot Wars J being called "Kouji Kabuto Dies in Lava!?"
The second to last AnimeMazinkaiser episode was also called "Kouji Kabuto Dies in Lava!" He almost does, but the Kaiser Scrandrer pulls him out.
Famously, some of the boxes for Ranma ½ described the series as a "sex comedy." Considering the lack of actual sex in the show, they probably meant "gender comedy."
Done many, many times in Italian dub openings (see also Spoiler Opening). Examples:
Kimagure Orange Road: the opening says Kyōsuke (dubbed Johnny in Italy) is psychokinetic and can also read minds. Ok, he's psychokinetic, but he can't read minds. (Probably this is due to a misunderstanding: in an episode, Kyōsuke and his cousin Kazuya switch bodies, and Kazuya can read minds). Furthermore, the song focuses on Kyōsuke's powers, but the plot is actually focused on the Love Triangle.
Saint Seiya: the first time it was aired in Italy (by Odeon TV, in 1990), the opening depicted it as the story of some guys fighting each other in a tournament to win the Sagittarius golden armor - repeating obsessively "only one in the end will win". Actually, the tournament only lasts the first few episodes, it's abruptly interrupted when the bad guys show up, and it's NEVER resumed, so that NOBODY wins the tournament. Oh, yes, sometimes the main character wears the Sagittarius armor, but only because the armor is somewhat sentient and decides to protect him - after all, he's The Hero.
Furthermore, the opening call the characters "Saints", but they are never called Saints in the Italian dub, only Knights.
Before it was broadcast, the Odeon TV spot announced it as a new cartoon coming "sulle ali della fantascienza più sfrenata" ("on the wings of the most unleashed science fiction"). But science fiction has little or no role in the plot.
In 1991 a new opening was aired: AGAIN, it focused around the tournament, around winning the golden armor as the only important thing, around "the stronger in the end will win". It included also nonsensical sentences such as "l'amicizia non ha più dignità" ("friendship has no longer dignity"): friendship among the main characters is a very important plot point, as in many similar stories.
The opening for School Days makes it look like a happy, up-beat love story with lots of Fan Service. It begins that way, but rapidly turns into something much darker.
Early promotion for the 13th Detective Conan movie heavily involved a scene with the most prominent antagonist of the series shooting Conan at point-blank range after having discovered his true identity. It turns out to be All Just a Dreambefore the opening credits.
Ninja Resurrection : The Revenge of Jubei is one of the most infamous examples. ADV Films put together a rather deceptive trailer and marketing campaign that made it look like the series was a sequel to Ninja Scroll. In fact, the two works have nothing in common except that the main characters both happen to be named Jubei. The series wasn't even originally titled "Ninja Resurrection" in Japan! Despite this, Ninja Resurrection sold like hotcakes on the strength of the deception. In fact, it sold better than the actual sequel to Ninja Scroll!
Sentou Yousei Yukikaze has a particularly cruel example: the Blu Ray edition features a trailer for a sequel with lots of new footage and even narration by one of the main characters. The only problem is that the sequel doesn't exist.
The creators of Gankutsuou decided to apply major changes to the anime in the very last moment. The result is that the official trailer features events that didn't happen or happened in a very different way, characters who didn't make it, and characters who look different from their final versions (Eugénie in particular).
Baccano. Funimation decided to parody the hell out of this trope and for the first 1/3 of the trailer made it seem like some sort of old black and white historical anime with mild, believable violence that makes one wonder why it's rated TV-MA. Then cut to a film reel ending and some guys staring boredly, then the real trailer with blood, big booms, guns, cut off limbs, ect.
First Squad had this pretty badly. Early trailers advertised, among other things, Nazi mechas. What we got were medieval people on horseback.
The trailers for Ookami-san said main heroine Ryouko Ookami was a new type of Tsundere. Actually she's quite typical (but still Moe).
The preview of the final episode of Death Note has Yagami Light laughing triumphantly while saying that he is Kira, followed by the title "New World", implementing that Light has won and he is going to change the world at his own disposal. The actual story has him beaten down to the bottom and every cop chasing him. The Downer Ending also reveals that he actually dies miserably having accomplished nothing at all.
May also be a mixed example with Covers Always Lie, but in Bleach, Nel's adult form is heavily and prominently featured in cover arts, anime openings, anime closings, video game trailers, and other media, despite the fact that it only appears for a couple chapters and plays almost no actual role in the story.
The trailer for the 4th episode of Katanagatari shows clips of the long-awaited fight between Sabi Hakuhei and Shichika (in which, among other things, a shark is bisected). Instead the episode is about Shichika's sister and concludes with Shichika and Togame talking about the fight with Hakuhei while eating dango. Apparently the fight was over 11 shades of awesome and would have been too much to show the viewers.
Wings of Honneamise Royal Space Force gave the impression of an action film to the North American audience. This slow paced drama made people realise the trailer was for the last ten minutes (that includes credits)
The first trailer of the Aniplex USA release also qualifies. Apparently, according to the comments, some people are still being tricked despite the infamy this anime has gathered on the internet.
Wolverine had an infamously inaccurate trailer, showing, among other things, Wolverine with a Mullet, looking several years younger than he really should, and fighting ghosts. The trailer was bad enough for the hardcore Marvel fans to deem the entire anime the work of the devil, and secretly directed by Hitler himself. God help you if you confess to actually watching and *gasp* not hating it with a firey passion.
The back of the case for Digimon Adventure: The Movie mentions in the synopsis "a wayward digimon kidnaps the Digi-Destined". While this in fact does happen in the original movie, the North American version of the movie is a mish-mash of the first three movies with an altered plot to link them together. So the kidnapping sub-plot of the third part of the movie never actually happens.
The trailers for Nisemonogatari showed Suruga's big bare ass fully uncensored, but once the series proper aired, it was censored by a weird grey blur or books. Particularly bad because Studio Shaft had never censored Fan Service scenes before, in fact the first season was fine with showing Hitagi's bare butt.
Black Rock Shooter (2012 anime) emphasizes new character Chariot in the trailers and the promotional artwork. Meanwhile, Strength only appears on one poster and is in fact the least prominent character displayed in that poster.Their importance in the series is completely inverted. Chariot is killed off in the second episode, while Strength turns out to be central to the plot. To an extent, this also applies to Chariot's other self Kagari (who diminishes in importance after the second episode), and Strength's other self Yuu (also central to the plot).