Handling Reincarnations can be tricky, so writers often need a shorthand to identify and confirm that two characters in a work share the same soul without resorting to outright giving them the same appearances. This characteristic can be physical/visual (such as reincarnations sharing a Birthmark of Destiny or other Distinguishing Mark, eyes, hair, or voices) or otherwise (such as liking the same song or sharing a niche hobby with their past lives). In the case of the latter, this trope is usually independent from but can be a sign of Past-Life Memories. The characters may or may not be aware of the tell, but the audience usually is. When the characters are aware, said indication can be used to test whether or not one character is a reincarnation of another.
There have been claims of this being the case in real life. Dr. Ian Stevenson, who researched many claims of past lives, wrote about a number of examples. Most were birthmarks that in some way matched wounds people said they had in past lives (mostly fatal ones). Whether or not this is the case of course remains debated, as the birthmark claims usually couldn't be confirmed by independent research later (most cases were children, and Stevenson said they "shifted", as happens when you grow).
Compare Reincarnation Romance, where two lovers are reincarnated. Morphic Resonance is a similar principle applied to shapeshifting. Said characteristic may be a Shared Unusual Trait or, if physical, a Mark of the Supernatural.
This list of examples has been alphabetized.
- One of the endings of Fantastic Children is this way. Having been reincarnated on earth another time, Tina meets a man that looks rather like Soran. She confirms this when she sees her name on his arm in Greecian, the language of their home planet during their previous lives. He responds with a smile.
- In Magical Girl Lyrical Nanoha Vivid, Einhart's heterochromia and silvery-green hair are an indicator of her having inherited the Genetic Memories and will of her ancestor Claus Ingvalt. This is treated as the closest In-Universe equivalent to reincarnation (actual reincarnation is impossible within the rules of The Verse).
- In No Game No Life, the Big Damn Movie features Riku and Shuvi, the predecessors of Sora and Shiro. On top of having huge physical resemblance and same voices, albeit with some minor differences like hair color and species difference, they notably share their successors immense talent at games. In fact it's implied Tet sought out Sora and Shiro because he suspected they were the reincarnations of these two legendary gamers.
- Nurse Angel Ririka SOS does this with Hair Color Spoiler. Ririka is blonde despite everyone in her family having dark hair; this winds up being an indication that she's the reincarnation of the original Nurse Angel.
- Fakir of Princess Tutu is the reincarnation of a fairytale knight sworn to protect his prince. To confirm this, he has a birthmark that resembles the wound that killed the knight.
- Spirit Circle:
- One of Fuuta's earliest past lives, Vann, received a cursed brand on his cheek from a witch (herself one of Kouko's past incarnations). This carries over into Fuuta's later incarnations as a birthmark, growing only slightly fainter each time. When the present versions of Fuuta and Kouko finally bury the hatchet, Fuuta's mark fades completely.
- Kouko herself gets this in reverse - when she received a forehead scar identical to that of her past life Koko, it became a trigger that unlocked her Past-Life Memories as Koko. This scar likewise fades at the end of the story.
- Yona of the Dawn: One of the many hints that Yona is the reincarnation of the Red Dragon Hiryuu is her unusual, flaming-red hair, which Hiryuu had in life after being incarnated as a human.
- The Ancient Egypt arc of Yu-Gi-Oh! features reincarnations who have more or less the same facial features and millennium artifacts as their modern-day Japanese counterparts — except for Kisara, a mysterious young woman with white hair and blue eyes. Between this appearance and Priest Seto's attachment to her, it becomes obvious that her "reincarnation" is the Blue-Eyes White Dragon.
- Astronaut Grimaldi's daughter from Heavy Metal witnesses the demise of the last Taarakian warrior as she vanquishes the Big Bad. Escaping her home just before it's blown to smithereens, Grimaldi's daughter discovers a featherless bird has come to her side. Her hair turns white in the moonlight, and she develops a ring-and-sword birthmark on her neck, which indicates that she has become the newest Taarakian warrior. Some closing exposition by August Schellenberg as the narrator verifies this spirit-transfer.
- Bear from A Dog's Purpose tries to invoke this. He remembers all his lives and finds himself back with one of his previous owners, Ethan. Bear tries to show Ethan that he's his childhood dog Bailey by doing the same tail trick Bailey did, but it takes a while for Ethan to understand its anything but a coincidence.
- The Laurel and Hardy film The Flying Deuces has a surprise Downer Ending with Ollie dying in a plane crash and Stan being disconsolate. After this, however, Stan meets a talking horse who wears Ollie's hat, and the two friends are reunited, after a fashion.
- In I Origins, reincarnations can be identified by unique results on new iris-scanning technology. The main character realizes that his ex-girlfriend was reincarnated into a little girl in India because they shared the same eyes.
- Reincarnation: Yuka's neck birthmark marks her as the reincarnation of a maid who was hung on the night of the massacre.
- The documentary Unmistaken Child features the non-physical version: a Tibetan monk seeks to find his master's reincarnation, and does this by testing children who respond in certain emotional ways to his master's possessions.
- Cloud Atlas: It is heavily implied that five of the six protagonists of the Nested Story are all the same soul (in the sixth story, the birthmark is on the deuteragonist instead), and are identified by their comet-shaped birthmark.
- In Great Alta Saga, the reincarnations of Jenna all have Mystical White Hair from birth.
- Warrior Cats: Hollyleaf and Leafpool recognize Cinderheart's way of flicking her paw as identical to Cinderpelt, of whom Cinderheart is a reincarnation.
- In The Years of Rice and Salt, the continuously reincarnating characters are identified by their shared initials, such as Kyu and Kokila.
- The Malazan Book of the Fallen: After at first not believing that the boy he is presented with is truly the reborn Sormo E'nath, cadre mage Kulp takes a good look at him and changes his opinion based on the boy's aura. For one, it's the aura of an ancient man. Additionally, Kulp smells on Sormo a ritual that only a truly old and powerful warlock could have undergone in his final years as preparation for his own death.
- Babylon 5: When a triluminary glows in the presence of Jeffrey Sinclair it is taken as a sign that he is the reincarnation of the Minbari hero and prophet Valen. Sinclair and Valen later turn out to be the same person in a Stable Time Loop.
- Implied in 7Days, where a villain with a birthmark under his eye dies and the episode ends with a shot of a newborn baby with the same birthmark.
- In Dreamfall Chapters, the first confirmation that Saga is a reincarnation of April Ryan is when she starts drawing pictures showing the latter's journeys, just as the latter herself did as a child.
- Mentioned as a possibility in Honkai Impact 3rd. Otto created an Artificial Human by mixing the genes of a long-deceased legendary Valkyrie, Kallen Kaslana, with that of a powerful Honkai Beast. He noticed that one of the bodies seemingly had Kallen's personality (instinctively protective of people). Otto wonders if she is Kallen's reincarnation, which doubts because the concept of "reincarnation" is unexplainable by known science. Nevertheless, he adopted said clone as his "granddaughter", called her Theresa, and raised her as a Valkyrie.
- Shin Megami Tensei IV: Apocalypse: Nanashi shares a similar trait with Akira of Shin Megami Tensei IV — they both have scars on their right cheeks, indicating that Nanashi is the reincarnation of Akira.
- At the end of SoulBlazer, the main girl has a goat named Turbo, who she names after a dog who was a Heroic Sacrifice because he "looked like Turbo". After the main characters leave, the goat follows; pausing to do a gesture that was attributed to the original Turbo; indicating he is a reincarnation.
- Cereal Soup: A Loading Screen tip describes one of the gods, Omni-Alpha, with having the ability to reincarnate with all the scars from his past lives.
- In the American Dad! episode "A Star is Reborn", an aging Hollywood actress believes Stan to be the reincarnation of her dead actor husband (who was known for his signature falls) after seeing him trip and avoid a fall from the marbles that she scattered in memory of him. She further believes it after being reminded of the way her husband eats hotdogs after seeing Stan eat one, among other mannerisms. Francine (who may or may not be the reincarnation of a starlet herself) comes to believe that it's the truth.
- Avatar: The Last Airbender: The Air Nomad method of recognizing the Avatar, the perpetually-reincarnated embodiment of light and peace capable of bending all elements, is by having their infant children pick four toys out of many. Every historical Air Nomad Avatar chooses the same four toys, known as the Avatar relics, so the infant who chooses said toys during the test is identified as the current reincarnation.