Gecko Ending

When an adaptation must have an ending, but is based on a work that has not finished yet, there are two possible solutions. One is to give the show some emotional closure without actually ending the plot in any significant way. Many fans will just complain this is a "non-ending" of sorts. When this involves a romance arc, the result can be either No Romantic Resolution or Maybe Ever After, which may or may not be satisfying.

However, some productions opt instead for a Gecko Ending—creating a conclusion/GrandFinale for the show out of whole cloth which resolves (or hastily buries) all the show's hanging threads and unresolved plot elements. Naturally, this requires that the viewers ignore many later revelations in the original work or it will make no sense, even if the series' plotline so far has been pretty similar.

There's also a third option - wait for the writer to get farther ahead - but that would involve waiting, and that's just unacceptable. Of course, you could always use Filler until they catch up.

Naturally, restarting the story at this point would have to involve either: a.) an extreme tangent to the original material, or b.) abandoning the plot so far and starting up an Alternate Continuity.

The trope name comes from the behavior of the gecko, which will, if its tail is cut off, grow a new one.

In anime, this often implies that the series Overtook the Manga, but only in the broader sense that there's no manga ending available, not in the sense that there isn't enough manga to fit into the anime. In fact, a movie, OVA, or short series may have a Gecko Ending even after compressing and omitting large parts of the manga.

Recently, some studios have averted this trope by timing the anime to end around the same time as the manga. By working closely with the creator, they can produce a faithful adaption of the ending before it's published, and in some cases before it's even been drawn. This is obviously rather tricky, so most studios still prefer one of the above options.

Not related to Gordon Gekko, Switching To GEICO, Straight From The Gecko, or The Gekkostate.

Anime and Manga

 * The Fruits Basket anime stops at a place in the manga where there aren't any plot bunnies left hanging, and before a new arc begins and a ton of new characters are introduced- around volume 6. The manga actually wrapped itself up nicely after 23 volumes with
 * Midori no Hibi. Fortunately, there was a story about halfway through the manga which needed only minor modifications to become a satisfying ending for the anime.
 * The Blue Exorcist anime goes in a very different direction from the manga after episode 15. Characters like the main character's mother and grandfather make an appearance and the Big Bad true intentions are revealed. Things that manga has yet to address.
 * The 2003 anime version of Fullmetal Alchemist created a completely new second half with help from the Mangaka.
 * A rather atypical example, it should be noted, since unlike with a lot of other series with Gecko Endings, the intention here was also to tell essentially an entirely different story, keeping only the starting point and the basic elements of the original. This was due to the mangaka believing, at that time, that telling the same story twice would be pointless (she eventually relented). That said, even if they had tried to follow the manga's actual storyline, given that the manga itself only ended shortly before the second anime adaptation, which aired several years after the first finished, FMA original would probably have had a Gecko Ending either way.
 * Mahou Sensei Negima pretty much has a Gecko Beginning, never getting past the very start of the story before winging it.
 * Twice, once for each anime adaptation.
 * More specifically, Akamatsu Ken seemed to have wanted to do an action series, but Executive Meddling made him do what was ostensibly a romantic comedy, which is what he was known for. The (first) anime completely abandons the manga as soon as the manga starts getting serious, keeping it purely about Fan Service, while the manga revels in its Mood Whiplash.
 * The Gecko Ending of the first anime had worse Mood Whiplash than the manga has ever done. It . At the least the manga generally eases into the dramatic portions...
 * Make that three times. The Manga ended up with a rushed ending that didn't tie together most of the loose plot threads, just like the anime. It simply lasted a lot longer and had a lot more meat to it before doing so. This, however, was a deliberate Take That at his publishers and the manga publishing industry in general, who were at the time engaged in a heavy-handed campaign to have Japanese copyright laws changed so that they could grab more of the rights and profits from their writers and artists.  Akamatsu deliberately drove Negima into a wall, plotwise, as a protest.
 * The anime version Great Teacher Onizuka generally followed the manga quite accurately at least to the point where the manga was when the anime was on air. The result is that the series gained a gecko ending in the last 2 episodes of the series to tie up all the loose ends and explain the actions of the class - something which didn't occur in the manga for a few more volumes.
 * Konjiki no Gash Bell!!
 * The Gash vs. Brago shot may have foreshadowed the final battle of the manga.
 * Flame of Recca condenses a 33 volume manga's first major arc into 42 episodes. In order to wrap up the plot, they have both the Big Bad  and the , proving once and for all that
 * Although the OVA seems to have fixed these issues.
 * The makers of the Gantz anime knew they'd have to make a Gecko Ending from the very first episode, and subsequently started planting hooks that would eventually become significant in the final arc, which was completely made up, right from the beginning. It's actually quite impressive seeing characters who appeared in the background of some early scenes showing up as major characters for the final game.
 * The televised anime of Hellsing follows the general plot of the manga relatively well for a few episodes. Unfortunately the manga had not progressed much further than those episodes by the time the anime was produced. Consequently, the anime's creative team had to essentially go with what they had for the remainder of the series, as well as add a Gecko Ending. What resulted was a totally different plot from that of the manga (which finished around 7 years after the anime first aired), several characters unique to the anime, a Big Bad that bears almost no relation to the one in the manga, and a quite strange ending that has several key characters experience rather different fates (ie. .)
 * The outcry for a more accurate and faithful anime translation resulted in the creation of Hellsing Ultimate, a series of OVAs that follow the manga extremely closely.
 * Airmaster: The anime finished three years before the manga, it was inevitable, though completely strange. The ending was almost a mix between a cliffhanger and the quick tying of strings.
 * Film example: Akira, in which the loose ends were tied up in a far different fashion than in the manga (and much earlier, story-wise).
 * Single episode example: to promote the then-recently released Kirby Air Ride, 4Kids aired a two-part episode of Kirby Right Back At Ya featuring the Air Ride machines from the game. The problem? Those episodes were aired right before the three-part Grand Finale that had just aired in Japan, and 4Kids was right in the middle point of the series in their dub at that point. Plus, by the end of the second episode they want to use to promote the game, the Warp Star and Cappy Town are destroyed. So what do they do to maintain the status quo in their dub? They took the lazy way out, added in some footage from other episodes, and handwaved the fact that their two-parter was All Just a Dream. Thus, they don't have to worry about the consequences of the episodes occurring too early in the dub's run.
 * The Elfen Lied anime mostly ties up the plot threads that had been opened so far and is quite faithful to the first chapters of the manga. However, it only manages to cover about half of the mangas storyline before diverging into its own continuity, thus missing out on most of the manga's major plot points and themes that were then only slowly being revealed.
 * Narutaru. The show was abandoned half-way through, leaving much of the story hanging, with the main villains barely appearing at all after the sixth episode and . Considering how things went in the manga from thereon, it may have been for the better.
 * Bokurano. Apparently the anime's director wasn't too thrilled with the original manga and decided to take it in his own direction; the fact that he could justify it by the manga not having ended yet was just a bonus.
 * Trigun is noteworthy for not only having a Gecko Ending, it has two key plot points to the manga which was finished about a decade later.
 * The manga of Nausicaa of the Valley of the Wind eventually ran on to seven volumes; the feature film included elements from the first two volumes and an original ending. This is something of an odd example, as it was originally imagined as a film and the manga was made so it could be adapted into a film.
 * X 1999 the movie and, to a lesser extent, the TV series.
 * Record of Lodoss War OVA, which received a gecko ending cause of budget restraints. The funny thing is the nature of this ending: It is the actual ending of the story, however with different characters. When they got the funding to make Chronicles of the Heroic Knight they basically told viewers to forget the second half of the OVA since they pick up the plot after the "War of Heroes" in the series. Which means the series in itself doesn't make sense if you don't know the OVA and it doesn't make sense if you know it but are unaware of the second half being a gecko. It still might not make sense to some viewers because of smaller inconsistencies due to the OVA also changing some events from the manga and novels, and thus missing the motive behind Ashram's anger in the TV series.
 * Since non-Japanese reading fans of the franchise lack access to the original novels, the easiest way for them to make sense of the events in Chronicles of the Heroic Knight is for them to regard it as a sequel to the Record of Lodoss War: The Grey Witch manga. It's not the best way to solve the confusion, but probably the easiest, at least for English-speaking fans.
 * Kare Kano ended up with one of these, as the author of the original manga was incensed by how the anime was handled and refused to allow another season.
 * Every season of The Familiar of Zero ever.
 * Here's a breakdown of how a season goes: the first two episodes are the exposition. The next 8 or so episodes are mostly Fan Service and lulz with some plot in them, although the plot element is rather insignificant for the most part. The final trio of episodes undergoes radical Cerebus Syndrome and goes from a tits and giggles Shonen fantasy/ romcom with a Magical Girlfriend who is an extremely violent Tsundere to a very serious drama.
 * Loveless's anime ended while the manga was still going, leaving us with a Mind Screw non-ending.
 * Busou Renkin has one of these in the manga due to an impending-cancellation-induced rush.
 * Claymore. Near the end of the series it became apparent there weren't enough episodes to reach the point in the story that would have provided both a satisfying climax and a canon end to the series. Thus small edits crept into the final canon arc helping to pave the way for a ridiculous and ultimately unsatisfying conclusion.
 * The Spiral ~Suiri no Kizuna~ manga was nowhere near a conclusion, let alone the answer to the series' two big mysteries, when the anime ended. On the bright side,
 * Tsubasa Chronicle, when animated (somewhat faithfully at first, to vehemently anti-canon later on) by Beetrain, "ended" the series at the end of Season 2, when In a dialogue between Kurogane and Fai, Kurogane asks if the journey will ever be over, and Fai responds that he doesn't want the journey to ever end.
 * The series had five OVAs produced that picked up where the last canon episode by Bee Train left off after the Rekord Country arc. The first three OVAs, Tsubasa Tokyo Revelations, continued exactly from that spot, which was good since those who didn't read the manga could still follow the story. Unfortunately, the second two OVAs, Shunraiki, picked up two whole arcs later after the Infinity and Celes arcs in the manga. Many fans who had not read the manga were pretty confused about what was happening.
 * Hell Girl. Not the anime—that came first. But the live-action show didn't run long enough to do the back half of the anime's storyline, so it had an original ending which was very different.
 * Eyeshield 21 anime stops right after the Final Battle between Sena and Shin. After some talk, the anime shows Sena being announced in the NFL, along with a few other characters, while the manga continues on with the Devilbats facing fiercer and stronger opponents in the Tokyo Tournament. The manga finished mid 2009, after a world wide football tournament where every major player in the series teaming up to take on the U.S.A. team. The manga ends with Sena, Kurita, Kotarou, Riku, Monta, Mizumachi, Unsui and Suzuna all going to Enma university together, with the rest of the players mixed and matched at other universities, and a Sequel Hook in the form of the Rice Bowl.
 * Soul Eater is a prime example. This manga series is still ongoing and releases a chapter a month. For instance, The anime series had  Though with Fullmetal Alchemist getting a manga faithful series reboot, it may very well be possible for Soul Eater to get the same treatment when it finishes.
 * Something like the first FMA, the anime split off from the manga just early enough to establish the differing storyline rather than just slotting one in once they reached the final few episodes. Which is fortunate, given using the Baba Yaga arc as it stands in the manga would have left far more plot threads hanging (one of which - the Sanzu Lines of shinigami - got used as New Powers as the Plot Demands /Ass Pull, rather than a plot point that is implied in the manga to be heading somewhere (though nowhere nice).
 * Given that the anime was made by Studio BONES (which also did the FMA anime) the possibility of a second anime series that follows the manga to the end (whenever that will be) is rather high. There's probably many fans who would love to see some of the newer arcs animated.
 * Excel Saga handled this in a rather unique way, doing away with the manga's plot completely in the animated adaption, and concentrating on the Widget Series side of the story, though it developed a plot of its own in the last few episodes.
 * Venus Versus Virus's anime ending was confusing to many fans, as the fates of the two main characters were unresolved.
 * Kashimashi: Girl Meets Girl's anime ending was a gecko ending, only volume 2 of the manga had came out when they began the anime. Oddly enough,the anime and manga endings are remarkably similar.
 * The GetBackers anime only did a fraction of what had been done in the manga by that point, with about a fourth of the series being one-episode fillers and the last eight episodes being a rehash of an earlier arc. The finale attempted to kinda-resolve the established mystery of the "gods" who controlled Mugenjou and Ginji's possible connection to them, but didn't bother addressing the other mysteries surrounding the supporting cast. Or the other main character, for that matter. Poor Ban almost comes across as Ginji's sidekick, instead of his partner. What makes this even more noticeable is that for the portion of the series that is directly adapted from the manga, it's a remarkably accurate and thorough transplanting of the action from the comic page to the screen, right down to tiny asides of dialogue that hint at greater mysteries to come... which the anime then never gets to.
 * Saiyuki's 2nd sequel, Reload: Gunlock went this road, especially with the author's health problems in recent years- interestingly, for a long time, it was thought that the direction the season Big Bad Hazel Grouse had gone in was completely random. ...And then the most recent volume of the manga came out.
 * The movie version of Fist of the North Star was made while the manga was still being serialized in Weekly Jump, specifically during the Raoh story arc. In the original theatrical release, the final battle ended with Raoh winning over Kenshiro, but spares his life after being dissuaded by Lin from killing him. Kenshiro leaves Lin and Bat to continue his search for Yuria, who mysteriously disappeared during the final battle for no reason (she is last seen with Bat and Lin), with no mention of her role as the last Nanto General or any of the other Nanto Seiken masters besides Shin and Rei. The alternate ending in the Japanese VHS release has Kenshiro ending the fight in a draw (just like his first fight with Raoh in the manga), but otherwise plays out identically to the theatrical ending.
 * D.N.Angel followed the manga somewhat closely for most of its run, then added a slightly rushed ending onto the end of it. Of course, given that the manga version has been put on hiatus enough times that it's STILL not finished, this is currently the only ending we even have.
 * Which could also be said for CLAMP's X/1999.
 * MAR is a rather odd example, in that the manga actually finished ahead of the anime. However the ending was very rushed bordering on anti-climatic. The anime however, not only expands on the ending but give a completely different final battle with most of the heroes killed (though brought back later) and one of them merging with her real world counterpart  to be with Ginta when he goes back.
 * The first Kuroshitsuji anime adaptation introduces an anime-original main villain even before the story has run out of manga chapters to adapt. This makes the grand finale not seem tacked-on.
 * NEEDLESS: The anime diverged from the manga in Episode 22 and ended with a final battle with Arclight, rather than having the group scattered.
 * Ouran High School Host Club's anime ended in such a way, with a two-episode plot about the club possibly closing down. While it doesn't really leave any loose ends, there is the frustration of not knowing who Haruhi picks...
 * It pretty heavily implies Tamaki, considering everything, but yeah, they left it open so a second season COULD start if they were ever picked back up.
 * Nagasarete Airantou's Anime totally overhauled the second groom catching contest so that Ikuto was fighting the four chieftains to meet the sea god in order to save his sister. In the process, he also.
 * Pandora Hearts pulled a BIG Gecko ending after the Ada arc that left anyone who was running through both simultaneously shocked. Especially considering that up until that point it had followed the manga flawlessly.
 * Highschool of the Dead: Anime ends with the main cast . The manga just finished with those plot points, although with in different ways.
 * It's not really a Gecko Ending. It's only the first season, after all.
 * Played with in Bobobo-Bo Bo-bobo, the final episode in the anime ends shortly after a new Big Bad was released, new villains with insane new powers were starting to show, and everybody is rushing to do battle with the new villains. It's even lampshaded in the last three seconds when Beauty exclaims, "Wait, this is the last episode?"
 * Karin.  The manga, on the other hand, went in a different direction much earlier, lasted longer than the anime, and provided a slightly more downbeat, but altogether more conclusive ending.
 * A weird instance with B't X. The anime's last 14 episodes (actually OVAs) were rushed out even though the manga still have several years to go. As such the final few Devil Knights are arbitrarily forgotten, Juggler doesn't undergo a Heel Face Turn, we never see the Machine Emperor, and Aramis just kinda... goes away. The manga's leadup to the final battle with Raphaello is, as you'd expect much better. But here's where the irony comes into play: in the manga, the final battle with Raphaello is insanely short and lacking any kind of fulfilling climax, whereas the anime's is a much more emotional affair complete with a Tear Jerker of an insert song.
 * Shaman King. Granted at the manga ended with a Gecko Ending too with Manta suddenly dreaming of the cast in fairy tale getups and heading off to rescue Princess Hao (your guess is as good as mine). But this was eventually rectifed with special edition volumes which properly closed the story. The anime which had largely diverged from the manga midway through the storyline ended with a typical final battle between Yoh and Hao and a Gondor Calls for Aid bit for Yoh to achieve victory. Though if anyone has read the manga you'll know  But hey it was a ending so meh.
 * 07-Ghost, notoriously so, ended before the actual adventure even started.
 * Ore no Imouto ga Konna ni Kawaii Wake ga Nai! has not one but two Gecko Endings on a row. Particularly bad because the second one finished what was touted as the "True ending to the novels!", but... it wasn't.
 * Cross Game is one of the first series to use the aversion method mentioned in the description. Since Mitsuru Adachi had the whole manga mapped out before it began, the anime producers were able to create a faithful adaption of the entire manga, even though it was nearly a year away from ending when the anime began airing. Both the anime and manga concluded within a month of each other, with nearly identical endings.
 * The anime of Psychic Academy only went through a third of the events of the manga, ending right after it had just finished defining the love triangle, without making the slightest effort to resolve it.
 * The anime of Omamori Himari ends with the demise of a powerful evil ayakashi, potentially giving hope for Yuuto's dream of human-ayakashi coexistence. It doesn't even attempt to resolve his Unwanted Harem problems.
 * Sora no Otoshimono averted this for the first season, simply using a badass manga chapter for its ending. The second season, however, completely made up the last two episodes, finishing a plot the manga didn't end until the next year. Meaning there's almost no manga plot left except the one used for The Movie. Yet they announced a third season. A Retcon dooms near.
 * Rave Master doesn't really have a gecko ending, it just...ends right after the introduction of Lucia, the true Big Bad of the series, is shown. The show had promptly been canceled due to low ratings and its assumed this was a gambit to get readers to check out the manga to see what happens next.
 * Which apparently worked, judging by the fact that the series ended its run with a whooping 35 volumes. Just for comparison, Lucia was first introduced as early as volume 11.
 * The DearS anime did this.
 * The Beelzebub anime followed the manga closely until the Akumano Academy arc, where it diverted greatly in the final moments of the penultimate episode, and it ended with.

Comic Books

 * The Archie Comics run of Teenage Mutant Ninja Turtles Adventures started with an adaptation of two episodes of the cartoon show, revolving around the search for three mystical gems called the Eyes of Sardath. The cartoon wrapped up the storyline quickly, with several more episodes of searching culminating with Shredder grafting the three gems onto his helmet. The comic went off on a completely different plotline, until 45 issues later when an alien robot named Sardath showed up looking for his eyes...

Film

 * The movie adaption for Scott Pilgrim was filmed before the final volumes of the series' release. The ending is based on early notes that didn't make it into the final copy of the book. But it still ends with
 * Kick-Ass. There's a big difference in the romantic subplot as well as
 * Lemony Snicket's A Series of Unfortunate Events was made into a feature film while the book series was still ongoing. The film's story loosely adapts the first three books, but its ending is original.

Video Games

 * The original 1988 Japanese computer versions of Snatcher were rushed for release, concluding the story on the cutoff point before third and the final act, even though a proper ending was already written for the game. SD Snatcher featured a very different version of the ending than what was actually included in the later CD-ROM-based remakes of the original Snatcher. For example, unlike the CD-ROM version,
 * The Genesis video game for The Pirates of Dark Water is an unusual case where the original never got anything close to an ending.

Western Animation

 * Single episode example: 4Kids' changes in plot from one episode of Winx Club from its original version created a loose end, necessitating a very unsatisfying Gecko Ending tacked on in the dub, without even bothering to explain things. In this case, they simply picked scenes from other episodes and redubbed them (which they've done quite a few times, although not for tacking on a new ending).