The Ar tonelico: Melody of Elemia Setting Encyclopedia is a large encyclopedia for Ar tonelico: Melody of Elemia authored by the GUST Staff and supervised by both the Producer and Director of the series, Atsunori Kawachi and Akira Tsuchiya, which compiles a large amount of the information used during the development of the game about its world and characters, which was released with the aim of answering questions about several aspects that were left unexplained during the course of the game. It's also known among the fandom by the Settei Book name.
The book itself is divided in the following sections:
Index and Artwork
Aside of showing the contents of the book, this section also compiles all of the pieces of artwork that were used in the products related to the game, such as the covers for the Drama CDs and manga tomes, at the time of its release.
Chapter 1: Reyvateils
This section talks in detail about each of the three main Reyvateils in the game: Aurica Nestmile, Misha Arsellec Lune and Shurelia. This includes commentaries from the Director about how each one of the Heroines were created and designed, initial drafts for each of them, keywords relevant to their personalities, quirks and role in the game's plot, information about their Costumes and Cosmospheres, and an artwork compilation showing all of the CGs in which they appear. It finishes with a brief overview over Aurica's and Misha's Level E Cosmospheres and explanations on their origins.
Chapter 2: Characters
This section covers in detail all of the characters aside of the Heroines, going from the main character, Lyner Barsett, to all of his party members, NPCs, and villains. All of them have also drafts showing their initial designs and some things that were never shown during the game, such as Flute Ross Loria's face.
It also gives a brief overview of the minor characters that show up during the game that didn't even get portraits drawn for them.
Chapter 3: Sol Ciel
This section is divided in four smaller sections due to being so lengthy, but in general, it has the purpose of explaining several matters and concepts about the region of Sol Ciel and the world of Ar Ciel in general.
Covers the timeline of Sol Ciel's history, explaining all the events that led this region of the planet to its current state. The explanations begin with the discovery of Sound Science and end with the attack on Skuwat Village, covering a period of around 800 years. This also gives a detailed account of what happened during the Grathnode Inferia, Mir's Rebellion and other important events.
It's a geographic overview of the First Tower of Ar tonelico and the Wings of Horus, explaining its most important locations and what are the functions of each of the facilities of the Tower, as well as explaining the transport systems used by the people that live in the region and the peculiarities of its towns and cities.
Explains the most relevant terms used in the game, in a similar fashion to the glossary the game had within itself. However, it also reveals some important details on Song Magic and the fact that the Teru are divided in several schools according to their familiars and powers.
Gives a brief explanation about the grammar and dialects of the Hymmnos language. It additionally has the lyrics to all of the songs that were featured in the game, while also showing the Feelings contained in each song, which are basically stories the composers, arrangers, lyricists and singers received from Akira Tsuchiya as the basis for them to compose the songs however they wished. It ends on a timeline that shows how the Hymmnos language was created and developed in-universe.
Chapter 4: Setting Information
This final section covers some material that didn't have much impact on the plotline of the game or its characters, but provide explanations for how the background of the series works. It's divided in the following subsections:
Wave Science Lecture
Explains the basics of Wave Science, which is the science of Ar Ciel that explains how everything in its universe works. It also gives a detailed explanation on how Dives work, the anatomy of the Reyvateils, and the theoretical principles behind Song Magic, Ar tonelico's inner workings, and the reasons behind the creation and usage of the Hymmnos language. It finishes by explaining what is the exact relationship between Aurica and Mir.
Interview with the Producer and Director
As the title says, it's an interview with Akira Tsuchiya and Atsunori Kawachi, where they explain a bit of how the development of the game started, reveal how the setting for Sol Ciel was originally going to be, the way in which Gust and Banpresto collaborated to make it a reality, and also they express their surprise at the fact that some claimed the game was either a galge or eroge.
Shows some of the character and enemy sprites used in the game, as well as a few enemies that were discarded during development.
Sidestory: The Queen of the Underworld
A short story where Misha converses with Spica Neal about her past, explaining some bits about Spica's wish to be the queen of the underground market and information networks of Sol Ciel, and the fact that she also had an archenemy since long ago.