History Main / OneDegreeOfSeparation

** ''Literature/{{Baccano}}'': It all started in a ship, in which that ship made some humans immortal. One of those immortals eventually became a member of a Camorra group in which his closest allies [[spoiler: eventually become immortal as well]] thanks to an old, immortal man from the ship, a man from another crime family, as well as two thieves. Those two thieves would later on go to a train ride where they befriend a young-looking boy who is also one of the immortals from the ship; and a young gang leader who happens to be under the radar of a hitman from another crime family, whose plans in the train ride get hijacked by a terrorist group led by one of the immortals from the ship. Said immortal's daughter happens to get the attention of a young conductor [[spoiler: who is actually a serial killer and has been killing several people in the train and fights with the hitman. Not to mention he's the adoptive brother of the Camorra group's closest allies. His adoptive brothers]] then come across the sister of the man partially responsible for making the Camorra group and their allies [[spoiler:immortal]]. Later on, she also takes in the young gang leader and his gang, as well the immortal's daughter from the train who then joins said gang; At one point, she also came across the two thieves. [[JigsawPuzzlePlot Confused yet?]] [[LongRunner Because that's just what the first few volumes (and the anime) have covered]].

** ''Literature/{{Baccano}}'': It all started in a ship, in which that ship made some humans immortal. One of those immortals eventually became a member of a Camorra group in which his closest allies [[spoiler: became immortal as well]] thanks to an old, immortal man from the ship, a man from another crime family, as well as two thieves. Those two thieves would later on go to a train ride where they befriend a young-looking boy who is also one of the immortals from the ship; and a young gang leader who happens to be under the radar of a hitman from another crime family, whose plans get hijacked by a terrorist group led by one of the immortals from the ship. Said immortal's daughter happens to get the attention of a young conductor [[spoiler: who happens to be a serial killer who's been killing several people in the train and fights with the hitman. Not to mention he's the adoptive brother of the Camorra group's closest allies. The conductor and his adoptive brothers]] then come across the sister of the man partially responsible for making the Camorra group and their allies [[spoiler:immortal]]. Apparently, she also takes in the young gang leader, his gang and the immortal's daughter from the train; and at one point, she also came across the two thieves. [[JigsawPuzzlePlot Confused yet?]] [[LongRunner Because that's just what the first few volumes (and the anime) have covered]].

* ''Fanfic/OniGaShikuSeries'': The amount of connections in this fic is kind of ridiculous. For example the KnightOfCerebus who kidnaps Izuku's mom used to go to school with Izuku's art history teacher, whom Izuku met while he was on a job from his boss to help the cousin of a woman who used to work for Izuku's uncle; the cousin is another former classmate of the history teacher. Said kidnapper used to share a prison cell with the former owner of Izuku's ''VideoGame/DragonQuestIII'' copy, which was given to him by Izuku's boss. Said kidnapper also used to be in [[spoiler:the Omi Alliance]] before going to jail. Who else used to be a member? Izuku's grandfather. Which is how Goro Majima met the family and why he's Izuku's HonoraryuUcle now. A third chain of connections is how Majima, by taking on a construction contract for UA, accidentally ruined the financial status of one of his nephew's future classmates for over ten years after the fact. And the random connections just keep on going. Everyone knows everyone in Musutafu and Kamurocho.

* ''Fanfic/OniGaShikuSeries'': The amount of connections in this fic is kind of ridiculous. For example the NightOfCerebus who kidnaps Izuku's mom used to go to school with Izuku's art history teacher, whom Izuku met while he was on a job from his boss to help the cousin of a woman who used to work for Izuku's uncle; the cousin is another former classmate of the history teacher. Said kidnapper used to share a prison cell with the former owner of Izuku's ''VideoGame/DragonQuestIII'' copy, which was given to him by Izuku's boss. Said kidnapper also used to be in [[spoiler:the Omi Alliance]] before going to jail. Who else used to be a member? Izuku's grandfather. Which is how Goro Majima met the family and why he's Izuku's HonoraryuUcle now. A third chain of connections is how Majima, by taking on a construction contract for UA, accidentally ruined the financial status of one of his nephew's future classmates for over ten years after the fact. And the random connections just keep on going. Everyone knows everyone in Musutafu and Kamurocho.

-->'''Zero:''' [[ForWantOfANail There are moments when a single snail can make a world go extinct.]]

* In ''Film/MadameWeb2024'', after their first encounter with Ezekiel, Julia Cornwall, Mattie Franklin and Anya Corazon all realize that they all somewhat know Cassandra Webb: Julia knows her as the paramedic from the hospital who saved her stepmother, Mattie was almost run over by her ambulance while on a skateboard, and Anya lives in the same apartment building as Cassandra. When they say how weird it is how they're connected, Cassie states it's the least weird thing to happen to her recently.

* ''Literature/GrandmasterOfDemonicCultivationMoDaoZuShi'': Pretty much every plot-relevant character is directly connected to each other by [[ReallyGetsAround blood]], [[PerfectlyArrangedMarriage marriage]], [[BloodBrothers sworn brotherhood]] or [[FamilyOfChoice adoption]]. Somewhat {{justified|Trope}}, as the story revolves around the five most notable clans, akin to nobility in the cultivation world, and it is common for nobles to be all related to each other.

* ''Webcomic/Rain2010'': Where should we start? Rain, back when she was Ryan, and Gavin attended the same elementary school and were best friends. After she moves to a new town with her Aunt Fara and starts attending a new school, she runs into Gavin once again. In that time, Gavin befriended Rudy, who [[spoiler: dates Rain for a while]], and became TheBeard for his sister Maria. They eventually break up and Maria starts dating [[spoiler: Chanel]]. Emily, the school's LovableAlphaBitch, used to date [[MayDecemberRomance a much older guy]] named Chase. Chase is revealed to be both Rain's older sister Kellen's ex-fiance and [[spoiler: the father of [[TeenPregnancy Emily's child]]]], while Emily also used to date [[spoiler: Maria]] and later becomes good friends with Rain [[spoiler: before they start dating as well]]. Meanwhile, Rain's older brother Aiken was engaged to Jessica, whose therapist, Vincent, is revealed to be [[spoiler: Fara's ex from years ago, back when Vincent [[UsefulNotes/{{Transgender}} was Vivian]]]]. Jessica later stays with Rain and Fara, befriending their downstairs neighbor Heather, whose younger [[AmbiguousGender sibling]] Ky is another member of Rain's friend group. Later on, Drew, who goes to the same school as Rain and Gavin, falls for Ky.

*** An and Haruka were childhood friends before the latter became an idol.

** The blacksmith who forged Enma, one of Kozuki Oden's swords, was an old man who lived in Zoro's home village. Coincidentally, said old man also forged Wado Ichimonji, Kuina's sword which was bequeathed to Zoro after her death. Zoro was acquainted with the old man, but it's not until the Wano Country arc that he makes the connection.
*** Oh, and Zoro is also a direct descendant of Ryuma.
** As it turns out, Dragon is personally acquainted with [[WorldsSmartestMan Vegapunk]], and both were friends with professor Clover. Vegapunk, for his part, used to work with Caesar Clown, Vinsmoke Judge and Queen before he worked for the World Government, and [[spoiler:has enough clout with the giants of Elbaf that they freely allowed him access to the books that they salvaged from Ohara]].
** And Shanks is friends with [[TheBusCameBack Dorry and Brogy]].

** Here, as well as during the subsequent Wano arc, the existence of a near-mythical crew "Rocks Pirates" is brought up - and what do you know, [[spoiler:virtually every present-day character that was a pirate in those days was either a part of the crew (Whitebeard, Kaido, Big Mom, Shiki, John, Bakkin supposedly, [[WildMassGuessing Shakky perhaps]]), or in opposition of them (Gold Roger and - presumably - his own crew). Many of the modern-day big names, such as Shanks and Blackbeard, were then directly connected to one of the afore-mentioned people. It really seemed like the focal point of the entire recent One Piece history]].

** The Pirate King Gol D. Roger left his mark ''everywhere''. Even twenty years after his death his influence still seems to reach every corner of the world. Just among the Straw Hat crew, Luffy (unknowingly) wears the hat Roger wore in his youth, his hero Shanks served on Roger's ship, his grandfather was Roger's [[FriendlyEnemy greatest rival]], he was trained by Roger's first mate during the TimeSkip, and his adoptive brother Ace is Roger's biological son. Shortly before the main story began, Jimbei had befriended Ace when [[FireForgedFriends they stalemated after a five-day battle]]. Franky's sensei was the one who built Roger's ship, the Oro Jackson. Brook had befriended the man who would become the Pirate King's onboard doctor, Crocus. [[GenerationXerox Usopp's father serves as the sharpshooter]] in Shanks' crew, who apprenticed on Roger's crew. The first real pirate antagonist the crew encountered, Buggy the Clown, also apprenticed on Roger's ship alongside Shanks. Robin's goal to discover the "true" history of the world and learn about the events of the "Void Century" has already been completely uncovered by Roger and his crew years ago. The connections just go on and on.

*** Speaking of Hajrudin, he was acquainted with Big Mom when she was banished from Elbaf. He was also friends with Stansen (the giant slave from Sabaody Archipelago), who after the TimeSkip has become Hajrudin's crewmate as his shipwright.
** Also in the Dressrosa arc we learn that Law's ParentalSubstitute [[spoiler: Donquixote Rosinante]] doesn't only connect him to Doflamingo, but also to Sengoku, as [[spoiler: Rosinante was Sengoku's adopted son]]. This in turn connects Law to Luffy, as Sengoku and Garp are friends.

** In the Reverie arc, many people whom the Straw Hat met throughout their journey meet up with each other discussing about their common friend. This ranges from Vivi, the Neptune Family, Riku Family, Coby, the Straw Hat Grand Fleet, Dalton and Doctor Kureha.

** Also during the Reverie arc, as well as the subsequent Wano arc, the existence of a near-mythical crew "Rocks Pirates" is brought up - and what do you know, [[spoiler:virtually every present-day character that was a pirate in those days was either a part of the crew (Whitebeard, Kaido, Big Mom, Shiki, John, Bakkin supposedly, [[WildMassGuessing Shakky perhaps]]), or in opposition of them (Gold Roger and - presumably - his own crew). Many of the modern-day big names, such as Shanks and Blackbeard, were then directly connected to one of the afore-mentioned people. It really seemed like the focal point of the entire recent One Piece history]].

* Another possible professional sports version, though it can't be worked out rigorously, was posited by veteran sportscaster Creator/BobCostas in a 2016 Creator/{{ESPN}} piece on Vin Scully, who at the time of publication was less than two weeks away from retiring from the [[UsefulNotes/MLBTeams Los Angeles Dodgers]] broadcast team... after having called Dodgers games since ''1950'', when the team was still in Brooklyn.

** This, of course, led to games like 6 Degrees of Creator/KevinBacon and 6 Degrees of [[UsefulNotes/AdolfHitler Hitler]] (where you pick a random Website/{{Wikipedia}} page and follow page links until you get to Hitler's page.)
* The professional sports version of this is a [[http://hfboards.com/showthread.php?t=512065 Sillinger number]], after journeyman ice hockey player Mike Sillinger. No player in the UsefulNotes/NationalHockeyLeague's more than 90-year history is more than six degrees from Sillinger, and at one point in the 2007-08 season, every single player in the then-30-team league had either played with Sillinger or had a teammate who had played with Sillinger. In case you're wondering, you can connect Sillinger to Kevin Bacon in four steps: Bacon was in ''Sleepers'' with Ron Eldard, who was in ''Mystery, Alaska'' with Tie Domi, who was on the Toronto Maple Leafs with Eric Lindros in 2005-06, and Lindros played with Sillinger on the Philadelphia Flyers from 1997-99.
* Another possible professional sports version, though it can't be worked out rigorously, was posited by veteran sportscaster Bob Costas in a 2016 Creator/{{ESPN}} piece on Vin Scully, who at the time of publication was less than two weeks away from retiring from the [[UsefulNotes/MajorLeagueBaseball Los Angeles Dodgers]] broadcast team... after having called Dodgers games since ''1950'', when the team was still in Brooklyn.
-->Six degrees of Kevin Bacon? It's probably two, and no more than three, degrees of Vin Scully -- to connect you in some way to everything in UsefulNotes/{{baseball}} history. Everything. He had to have known somebody ... who knew Cy Young.[[note]]Young's last game was in 1911, and he lived until 1955.[[/note]] He had to have known somebody who probably met Ty Cobb.[[note]]Who last played in 1928.[[/note]] Ty Cobb lived until 1961. If he didn't know Walter Johnson, he sure as hell talked to somebody who batted against Walter Johnson.[[note]]Johnson's last game was in 1927; he died in 1946, before Scully started his broadcasting career.[[/note]] ... So there is no significant baseball personage that Vin Scully either didn't know or potentially knew someone who knew them.

* Creator/MichaelCaine claims that everyone he knew as a struggling actor in London during Sixties ended up becoming famous like him:
-->I was friends with Stan Getz, and Lionel Bart, who wrote Oliver! The painter Francis Bacon lived next door. He always tried to get me into his studio to paint me, but he was very gay and I thought, “I’m not going up there.” An actor called David Baron said he was going to write a play, and I said I’d act in it. He called it The Room and he did it under his real name, Harold Pinter. In the sixties, everyone you knew became famous. My flatmate was Terence Stamp. My barber was Vidal Sassoon. David Hockney did the menu in a restaurant I went to. I didn’t know anyone unknown who didn’t become famous.

* In talking to just about anyone over 40 involved in the boxing/fighting community in New York's Capital Region you might get the impression that everyone knew Mike Tyson before he was famous in one way or another. Ask around any gym in the area and there's a good chance someone trained with, promoted, interviewed, or fought Tyson before he was a household name.
* In the corporate world, government service or the miltiary, a low ranking employee or soldier may be only a few people away from the CEO, president, prime minister etc.