In the wake of the Cold War era and the memories of the great wars still fresh in the minds of people, they have become less and less tolerant of the death of soldiers in battle while countries with huge militaries, such as America and China, have been unable to give up their army munitions industry. With such conditions, the need for unmanned weapons to fight in wars instead of humans has arisen. However, as no countries export weapons to Japan, Japan's defense technology has become too weak and, eventually, Japan had to buy new equipment from America. Although, formally, America is supposed to work together with Japan on developing new technology. However, in reality, Japan was only given outdated equipment. Thus, the need for Japan to develop its own technology came.
«Project Alicization», a top-secret government project run by [[w:c:swordartonline:Rath|]], a company affiliated with the Japan Self Defense Force (JSDF), was started to create the first highly adaptive, «Bottom-up AI». By using a 4th-generation [[w:c:swordartonline:FullDive|]] machine, called the «Soul Translator» (STL), Rath succeeded in copying the Fluctlights (what the scientists believed to be the particles that contain the human soul) of twelve newborn babies, creating a «Soul Archetype», a non-developed Artificial Fluctlight that could be copied to create new Artificial Fluctlights, which would then need to be nurtured to mature into an individual. For this reason, a virtual world, codenamed «Aunkai», was created with Professor Akihiko Kayaba using the same [[w:c:swordartonline:Cardinal|]] system he used as the brains for the game, «[[w:c:swordartonline:Sword Art Online|]]», which was then transferred into the Soul Translator via its «Mnemonic Visuals» feature.
Aunkai is set in a past era when science and philosophy were just being discovered, but instead of recreating a past era, limited terrain and certain customs were introduced so that the inhabitants of the world would form their own society.
The inhabitants of Aunkai recognize a variety of gods, however, regional differences have given rise to numerous denominations of the same god.
- The Primordial God and Goddess (一次の神と女神, Ichiji no Kami to Megami?), also known as the Divine Couple of Creation (創世の神配偶者, Sōsei no Kami Haigūsha?) - the original god and goddess unique in which they are the only shared deities between all of the original five states and their successors. The Primordial God is known as Gebur (ヤェブール, Yebūru?) derived from the Old English "ġebūr" - "farmer", and the Primordial Goddess is known as Burwyf (ブールワィーフ, Būruwīfu?) derived from Old English "būrƿif" - "farmwife". They are credited for creating and teaching the original sixteen ancestors of the Beorns, the Haelaths, which gave humanity its greatest distinction from the beasts.
- The Sky and Earth Deities (天と土の神, Ten to Do no Kami?) - the second generation married couple, usually credited for the creation of the world as a whole, or for becoming the world itself in order to allow humans to inhabit it. They are often credited for creating the many fore-bearers of the Maegas.
- In Svarbyrdheimr, they are the Sky God Skȷ́a (天神スキャ, Ten Shin Sukya?) and the Earth Goddess Hjórð (土神ヒョールズ, Do Jin Hyōruzu?).
- In Albatigrum, they are the Sky God Cailom (天神カイロム, Ten Shin Kairomu?) and the Earth Goddess Tella (土神テッラ, Do Jin Terra?).
- In Ibrizaraf, they are the Sky Goddess Ne'ē (天神ニェエー, Ten Jin Nyeē?) and the Earth God Gebbw (土神ゲッブー, Do Shin Gebbū?).
- In Raktavi, they are the Sky God Akāś (天神アカーシュ, Ten Shin Akāshu?) and the Earth Goddess Dhátī (土神ダーティー, Do Jin Dātī?).
- In Kiyotō, they are the Sky God Tiān (天神ティアーン, Ten Shin Tiān?) and the Earth Goddess Tū (土神トゥー, Do Jin Tū?).
- The Sun and Moon Deities (日月の神, Jitsugetsu no Kami?) - the third generation married couple, more often or not brother and sister, or alternatively, a pair of twins. There is a common tale of a falling out between the two which led to them becoming separated by the night and day, only to make amends and reconcile temporarily during the eclipse.
- In Svarbyrdheimr, they were the Sun God Shuén (日神シュエーン, Hi Shin Shuēn?) and the Moon God Ménô (月神メーノー, Tsuki Shin Mēnō?).
- In Albatigrum, they were the Sun God Usil (日神ウセィル, Hi Shin Usiru?) and the Moon Goddess Lusa (月神ルーサ, Tsuki Jin Rūsa?).
- In Ibrizaraf, they were the Sun God Samšu (日神サムシュ, Hi Shin Samushu?) and the Moon God Ta'lāb (月神タラーブ, Tsuki Jin Tarābu?).
- In Raktavi, they were the Sun God Sūrvya (日神スールヴヤ, Hi Shin Sūruvuya?) and the Moon Goddess Candrā (月神チャンドラー, Tsuki Jin Chandorā?).
- In Kiyotō, they were the Sun Goddess Ri (日神リィ, Hi Jin Ryi?) and the Moon God Jyue (月神ジュエ, Tsuki Shin Jue?).
- The Storm God (嵐の神, Arashi no Kami?) and the Fire God (火の神, Hi no Kami?) - (blood) brothers or siblings and more often than not, rivals. The most common myth among their misadventures, the Fire God steals the sacred flame from the hall of the gods and gifts it to humanity, often at the cost of incurring the Storm God's wrath in the process.
- In Svarbyrdheimr, they were the Storm God Þónarr (嵐神ゾーナッル, Arashi Shin Zōnarru?) and the Fire God Fjôr (火神フョール, Ka Shin Fyōru?).
- In Albatigrum, they were the Storm God Dyeus (嵐神ヂヤェウース, Arashi Shin Djiyeūsu?) and the Fire Goddess Eosta (火神エオスタ, Ka Jin Eosuta?).
- In Ibrizaraf, they were the Storm God Ǧaniē (嵐神ジャニエー, Arashi Shin Janiē?) and the Fire God Efrīt (火神エッフリート, Ka Shin Effurīto?).
- In Raktavi, they were the Storm God Índrus (嵐神イーンドリュス, Arashi Shin Īndoryusu?) and the Fire God Agnís (火神アグニィス, Ka Shin Agnyisu?).
- In Kiyotō, they were the Storm God Ran (嵐神ラン, Arashi Shin Ran?) and the Fire God Huo (火神ホュオ, Ka Shin Huo?).
- The Ocean God (海の神, Umi no Kami?) and the Underworld God (闇の神, Yami no Kami?) - the overlords of the second quarters of the world after the Earth and Sky Gods. There are no set series of relations between these two groups of deities, however the two gods under this group are usually siblings and often act in tangent to one another whatever their relationship to the other groups may be.
- In Svarbyrdheimr, they were the Ocean God Sǣgja (海神サーエギャ, Umi Shin Sāegya?) and the Underworld Goddess Ránð (闇神ラーンズ, Yami Jin Rānzu?).
- In Albatigrum, they were the Ocean Goddess Marin (海神マリン, Umi Shin Marin?) and the Underworld God Orcus (闇神オルカス, Yami Jin Orukasu?).
- In Ibrizaraf, they were the Ocean Goddess Yahwm (海神ヤホゥーム, Umi Jin Yahūmu?) and the Underworld God Wešir (闇神ワェシル, Yami Shin Weshiru?).
- In Raktavi, they were the Ocean Goddess Udrá (海神ウードラー, Umi Shin Ūdorā?) and the Underworld God (闇神, Yami Jin?).
- In Kiyotō, they were the Ocean God Hai (海神ハイ, Umi Shin Hai?) and the Underworld Goddess An (闇神, Yami Jin An?).
- The God of Steel (鋼の神, Kami no Hagane?) and the Great Dragon (大龍, Ōtatsu?) - the first hero and/or original warrior and his greatest enemy. In all but Kiyotō, the God of Steel is a legendary figure of Order who represents national pride and is often presented as the ancestor of the nation's leaders, while the Great Dragon is a figure of Chaos and the enemy of humanity. In Kiyotō, however, their roles are swapped.
- In Svarbyrdheimr, they were the Hero Zigfrieð (勇者ぜゴィフリーッゾ, Yūsha Zigofurīzzo?)and the Iron-skinned Frænir (鉄皮のフラエニル, Tetsukawa no Furaeniru?).
- In Albatigrum, there are several different myths:
- In its successor state Flavan, there is King Altria (アルトリア王, Arutoria Ō?) and the Twin Red and White Dragons of Domination (双子の赤と白の龍の支配, Futago no Aka to Shiro no Ryū no Shihai?).
- In Maeventum, there is the Demigod Alkaios (亜神アルカイオス, Ashin Arukaiosu?) and the King of Monsters Tuphaōn (怪獣の王トゥーファオーン, Kaijū no Ō Tūfaōn?).
- In Ibrizaraf, they are the Spirit of War Belhram (戦争の精神のベルホラム, Sensō no Seishin no Beruhoramu?) and Original Sin Aun'weor (原罪のアウンワェオル, Genzai no Aunweoru?).
- In Raktavi, they were the Avatar Ángrra (天降アーンゴッラ, Amakudari Āngorra?) and the Evenloper Ahitrá (立ち込めるのアヒトラー, Tachikomeru no Ahitorā?).
- In Kiyotō, they were the Prince Zūn (ズーン王子, Zūn-ōji?) and the Four-Headed Dragon King of the Earth, Etsu (地球の四頭の龍王エツ, Chikyū no Yotsu-tō no Ryūō Etsu?).
In the world of Aunkai, there are even many minor deities that are unique to each state with no external equivalent in other nations. In fact, there are so many that it is impossible to count or name them all.
- Main article: Aunkai/Timeilne
All beings of Aunkai share a common calendar because they all believe that the World began in the same year. This calendar is known as the Imperial World Calendar (上界暦, Jōkai-reki?). This calendar begins dating immediately following the full creation of Aunkai and the birth of the sixteen initial Artificial Fluctlights. As the time flow in Aunkai can be changed via the rate of Fluctlight Acceleration, the IWC cannot be aligned with the time of the real world.
Like its Japanese equivalent, the IWC has twelve months per year and, like the Japanese calendar, the names of the months are derived from the number of the month, for example, the equivalent of January is the 1st Month (一月, Ichigatsu?), the equivalent of February is the 2nd Month (二月, Nigatsu?) and so on.