In 2026, four years after the infamous Sword Art Online incident, a revolutionary new form of technology has emerged: the Augma, a device that utilizes an Augmented Reality system. Unlike the Virtual Reality of the NerveGear and the Amusphere, it is perfectly safe and allows players to use it while they are conscious, creating an instant hit on the market. The most popular application for the Augma is the game Ordinal Scale, which immerses players in a fantasy role-playing game with player rankings and rewards. Following the new craze, Kirito's friends dive into the game, and despite his reservations about the system, Kirito eventually joins them. While at first it appears to be just fun and games, they soon find out that the game is not all that it seems...
In a world, where the deities have descended from the heavens lies the town of Orario that features the Dungeon, which contains an assortment of monsters from goblins to dragons. Adventurers slay those monsters and take their shards, which are then used to craft magic items. To become an adventurer, people join groups called Familia. Each of which is named after and serves a resident deity. The adventurers and their attributes and abilities are ranked by level, improved by experience and supervised by their Familia's deity.
Bell Cranel, a novice adventurer, is the sole member of the Familia under the goddess Hestia. After being saved by top level adventurer Ais Wallenstein of the Loki Familia, he falls in love with her and decides to improve and become worthy of her attention. All the while mostly unaware that other girls, deities and mortals, also develop feelings for him. Especially Hestia herself.
In the near future, a Virtual Reality Massive Multiplayer Online Role-Playing Game (VRMMORPG) called Sword Art Online has been released where players control their avatars with their bodies using a piece of technology called Nerve Gear. One day, players discover they cannot log out, as the game creator is holding them captive unless they reach the 100th floor of the game's tower and defeat the final boss. However, if they die in the game, they die in real life. Their struggle for survival starts now...