Ret-Gone/Anime and Manga

Examples of in  include:

CLAMP crossover 'verse

 * In the end of the Clow Card arc of Cardcaptor Sakura, Sakura is threatened with something like this should she fail: no one will actually be gone, but everyone will forget that their most beloved person ever meant anything to them.
 * Tsubasa Reservoir Chronicle and ×××HOLiC (also CLAMP series) are connected by a Ret-Gone in which of Tsubasa, the son of reincarnated in the past , gave up his existence in his home world for the  . In order to fill the gap this left in space-time, a new son (who had not previously existed in any world) was created for  ,  .   existence is therefore precarious and could be erased by   death or by the Tsubasa gang correcting the space-time disturbance. The point of Holic has been for   to develop connections to other people that will anchor him to existence when the endgame comes.
 * Additionally, this almost happens to the "twins" described above when their parents have a Critical Existence Failure upon the death of their creator, as when he dies, their parents technically never existed once again, just as they were retconned in originally. The twins end up making a Deal with the Devil just to continue having existed.
 * Also,  of xxxHoLic suffers this once she re-dies. She actually died centuries ago, but a Reality Warper told reality to ignore that for a while. When she sells that "reality ignore my death" effect in a Deal with the Devil of her own, all of a sudden, to most people it is as if she had never kept on living for hundreds of years.

Pretty Cure

 * In Futari wa Pretty Cure, the three Seeds have this effect, but the evidence was pretty much all faked in the first place—each sprang into existence at the beginning of the same episode where his/her Ret-Gone happened—so it's justified as a non-lethal case of No Ontological Inertia.
 * In Futari wa Pretty Cure Max Heart, this briefly happens to Hikari, but it's a milder form, as Nagisa and Honoka are able to snap people out of it merely by mentioning her.
 * In Futari wa Pretty Cure Splash Star, when Michiru and Kaoru die, only Saki and Mai remember they ever existed, as Saki discovers when she tries to tell her sister Minori that Kaoru (who Minori was close to) is gone.

Sailor Moon

 * Happens to ChibiUsa in both versions of Sailor Moon that she is in; in the anime it's due to  in the manga it's due to  . She also gets retgoned after   In the manga, contrary to standard Grandfather Clauses, ChibiUsa is able to survive for an unusual amount of time after the point where her birth is made technically impossible. The future just becomes very stormy and unstable. In the anime version of this she's almost entirely retgoned however, vanishing from photos. The Sailor Senshi still seem to remember her however, they just can't tell things that are supposed to show her have changed.
 * Chibi-Usa survives because when Galaxia kills Mamoru, she just takes his Sailor Crystal. At that point, it's still possible for him to be revived . However once he's thrown into the Cauldron, he's pretty much dead until Sailor Moon defeats Chaos.
 * There's a fanfic where Usagi gives birth to a different child in place of ChibiUsa. Said child, after over nine hundred years of living in the shadow of a sister who never existed, eventually manages to Interestingly, this is also one of the few fics to suggest that Usagi would be upset by this situation.

Other works

 * This is the fate of at the end of Part 6 of JoJo's Bizarre Adventure. By using his newfound power of  the universe loops back on itself and reality is reset. However, as he is killed before completing the loop, the universe snaps back into a slightly altered version, and  is nowhere to be seen.
 * Shakugan no Shana has bad guys which consume people's power of existence. In order to prevent a shock to the reality fabric, placeholders ("torches") that resembles the original person are left behind. "torches" slowly burn out, becoming increasingly lethargic while all traces of their existence begin to disappear. At the beginning of the series, Yuji desperately, but futilely, tries to keep a classmate-turned-torch alive and continuously involved with their friends, but their attention inevitably drifts, until she finally fades away.
 * Happened to Chikane from Kannazuki no Miko as requirement for the save-the-world ritual... well, until The Power of Love and The Promise shook hands with each other to Screw Destiny while subverting the Bait and Switch Lesbians trope that anime writers loved so much back then.
 * The Movie of Haruhi Suzumiya -- The Disappearance of Haruhi Suzumiya—centers around about what you'd expect.
 * Yu-Gi-Oh! GX:
 * The end of the Revolutionary Girl Utena manga has Utena erased from the memories of the entire cast, with the exception of Touga, who mourns her passing worse because he cannot share his mourning with anyone. Only just then, Chuchu dresses up like Utena, and then Anthy walks by, now dressed in a boy's uniform like Utena had worn, so obviously some things have changed - and, as she says, Utena is not gone, but out there somewhere.
 * Same happens in the anime series (minus Chuchu) and Anthy sets off to find Utena again, implying that she wasn't so much "erased" as "moved away" from the other characters' world, which signifies her transition from childhood to adulthood.
 * At the end of Serial Experiments Lain.
 * Tenchi in Tokyo,
 * This is the favored tactic of Enfant in Madlax, who can effectively manipulate all information channels on the planet and, thus, erase all traces of anyone's existence, like they did e.g. with Maclay Marini.
 * Higurashi no Naku Koro ni has this happen in Rei, since
 * In the current story arc of Kinnikuman Nisei, set in the past, Brocken Jr. loses his right arm in a match, thus removing his trademark Red Rain of Berlin attack. In the next match, Jade attempts the move and is shocked to find he can't do it. Looking at a photo shows that Brocken Jr.'s hand is now a hook, therefore Brocken could never have taught the move to Jade. After some time for Jade's mind to adapt to his new memories, he now knows a leg-based version of the move: Brocken's Repatriation.
 * in Clannad. Gradually, everyone forgets that she's been running around the school lately and becomes unable to see or remember her. Eventually, only Tomoya remembers her.
 * Bleach: Still, she's essentially Ret-Gone. Because she's a   she's probably never going to be brought up in canon again, meaning she's never going to be re-introduced to the cast.
 * Also,
 * This is essentially the power of  in Saiyuki, as he shows Sanzo first-hand: literally, 'the power of nothingness'. It also extends to things, though, not just people, but the effect it has on people is what makes it fit the trope.
 * In an episode of Kirby Right Back At Ya!, no one was able to recognize Escargoon when the monster Erasem entered his body, although he never actually disappeared.
 * In Nabari no Ou, this is 's main goal. He.
 * In Puella Magi Madoka Magica, this happens to
 * Time Stranger Kyoko has this happen to the titular character.  She gets better.
 * In Darker than Black,
 * The fate of Kanshuu's victim on World Embryo.
 * Whether it belongs here or elsewhere (there IS an anime though I've not seen it) the Visual Novel One: To the Radiant Season has this as the major plot. You are disappearing from everyone's mind and vanishing from the Earth. The only thing that can bring you back is if you've made a connection with a girl enough for her to remember you.
 * One Piece:
 * An incomplete version occurs in the Dressrosa arc courtesy the powers of the Hobby-Hobby Fruit wielded by Sugar. Her powers allow her to transform anyone she touches into LivingToys, which she can then place under her control. A side-effect of this power is all memory of who she transforms is removed from other people. Physical evidence, such as written reports or statues, still remain.
 * It's frighteningly easy for Ain - from the 12th movie - to RetGone a foe. Her Devil Fruit power can make someone 12 years younger with each use (and she does not have to touch a victim to use it), and can potentially erase a person from existence via multiple uses by reversing them past their birth. While she's never done so on-screen, she tends to use it as a threat after displaying what it can do. And it works. Even the Straw Hats, who usually don't fear death, backed off after she reduced Nami to an eight-year-old and explained what would happen if she did it again.
 * In Dragon Ball Super, Beerus does this to Zamasu, eradicating him in Universe 10 and splitting the timeline, undoing all the damage he did in the current timeline. Course, the guy was really asking for it.
 * It's frighteningly easy for Ain - from the 12th movie - to RetGone a foe. Her Devil Fruit power can make someone 12 years younger with each use (and she does not have to touch a victim to use it), and can potentially erase a person from existence via multiple uses by reversing them past their birth. While she's never done so on-screen, she tends to use it as a threat after displaying what it can do. And it works. Even the Straw Hats, who usually don't fear death, backed off after she reduced Nami to an eight-year-old and explained what would happen if she did it again.
 * In Dragon Ball Super, Beerus does this to Zamasu, eradicating him in Universe 10 and splitting the timeline, undoing all the damage he did in the current timeline. Course, the guy was really asking for it.