When an author has multiple popular works under their belt over the course of their career, it can sometimes become possible to notice commonalities or recurrent ideas within their repertoire. When considering the works of Hiro Mashima, the author of Fairy Tail and Eden's Zero; for instance, the first thing that comes to mind is how similar characters from different Mashima works look identical and serve similar roles to each other in their respective universes.
Sometimes it's intentional, sometimes not; however, when it is, authors find incredible ways to connect disparate works in their own catalogues – be it literal crossovers, Easter eggs or a secret third thing combining the two, authors find interesting ways to bring their works together, and in the case of Ryohgo Narita (BLEACH: Can't Fear Your Own World), a simple word is all it took to connect his two most successful works – Durarara!! and Baccano!. Here's the run-down on these two brilliant titles, and the explanation as to how they're connected.
Pre-Game
Before getting into the specifics regarding plot, characters and the like, it is probably a good idea to touch base with the basic aspects of both titles. The most important aspect with these two series is the fact that they both feature ensemble casts, meaning that a characteristic of both Durarara!! and Baccano! is a large cast of characters with vastly varying personal experiences and viewpoints. Both series feature a good mixture of realistic and fictitious elements, many of which hinge on the mysterious or the supernatural, and are largely central to the narrative due to the characters all having some kind of relationship with the element. In Durarara!!, the sighting of the Black Rider connects all the characters in some way, and it exists in the realm of urban legend in the initial stages of the series. Baccano! follows a path in history forged after the creation of an elixir capable of granting eternal life, and has a vast amount of events occur aboard or around the transcontinental train known as the Flying Pussyfoot. Both series' mixture of fantasy and realistic elements, as well as interestingly interwoven characters and plot lines make them particularly brilliant in their approach.
Baccano!
Set in Chicago in the early 1930s, Baccano! is centered on the transcontinental train known as the Flying Pussyfoot, which becomes the site of a series of bloody conflicts resulting from an ensuing war between mafia groups, and the centuries-long quest to find (and control) an elixir known to grant immortality. The series follows a number of timelines, with the main series of events being kick-started aboard the Adenna Avis, with the quest of a group of alchemists to find immortality. However, immortality comes at a hefty price, and the actions of those alchemists reverberate to the present day.
The anime is based on author Ryohgo Narita's light novel series with the same name, initially published in February 2003 in Dengeki Bunko Imprint, under ASCII Media Works. There are currently 22 published volumes, with the series' running from 2003 to 2008. The title "Baccano!" comes from the Italian word "Bakkāno", meaning "ruckus", and is possibly in reference to the multiplicity of perspective, as well as the variety in the series' explored time periods, characters and even settings, not to mention the vast number of seemingly unrelated incidents that make up the progression of the story.
Durarara!!
Durarara!! follows a teenager named Mikado Ryūgamine, who is moving to Ikebukuro in order to enjoy a more exciting daily life and attend Raira Academy with his childhood best friend, Masaomi Kida. Hearing of the various incidents and supernatural occurrences that happen in this entertainment district in Tokyo, Mikado calls Kida and meets him on his first day in the area. While Kida shows him around, he tells Mikado about various individuals he does not want to mess with, including the bartender with superhuman strength, Shizuo Heiwajima; the shady information broker Izaya Orihara; and even about an ensuing gang war taking place between the Yellow Scarves; Blue Squares and a decentralized, amorphous organization known solely as "The Dollars". Kida also tells Mikado about the elusive "Black Rider", an urban legend in the streets of Ikebukuro that speaks of a headless motorcycle rider dressed in all black riding an all-black motorcycle. Mikado has the fortune of witnessing the urban legend for himself on his first day, which only serves to show him that moving to Ikebukuro for excitement was the right decision.
The Durarara!! light novel series was first released in April 2004 in Dengeki Bunko Imprint, under ASCII Media Works and ran until 2014, with a sequel series titled Durarara!! SH starting that same year. The manga adaptation of Durarara!! was serialized in Square Enix's Monthly GFantasy in April 2009, with the anime series produced by Brain's Base coming out in January 2010. While it is commonly understood that the title is onomatopoeia for the revving of an engine (supported by the association of motorcycles with Celty Sturluson; the "Headless Rider"), but Narita claims that the title has no meaning and is just a random name he gave his editor at an early stage in the editing process. Another possible connection between the commonly understood meaning of the title, "Durarara!!" is that it is a stuttered, unfinished utterance of the word "Dullahan", which of course brings it back to the motorcycle idea.
The Dollars Connection
As the first season of Durarara!! progresses, one comes to know various characters and their interactions in the underbelly of Ikebukuro, and how the characters are actually connected. Masaomi Kida's connection to the Yellow Scarves is information that is provided early; however, it later comes to be known that the unassuming main character of the series, Mikado Ryūgamine, is actually one of the series' most influential entities – the de facto leader of the elusive colourless gang known as "The Dollars".
By the end of the first season of Durarara!!, everyone and their grandmother is a member of the gang due to admission being based on anonymous sign-ups on a mysterious website. The password used to enter the Dollars' website in Durarara!! is seen when characters type it in, and it is none other than the title of author Narita's previous famous ensemble cast novel series: "Baccano!". Real-life anime and manga, not to mention other entertainment media and their respective bodies are referred to by some ot the characters in Durarara!! (like Spice and Wolf, for example), meaning that the events of the series take place in some kind of alternate reality, but it also means that it is fully possible for Baccano! to exist in the Durarara!! universe the way it does in our own.