In 2026, four years after the notorious Sword Art Online debacle, a groundbreaking technology surfaced: the Augma, an AR‑enabled device. Unlike the Virtual Reality of the NerveGear and Amusphere, it is entirely safe, letting users engage while fully awake, instantly becoming a market sensation. The most sought‑after Augma app is Ordinal Scale, a fantasy RPG that offers player rankings and rewards.
As the trend spreads, Kirito"s friends plunge into the game; despite his doubts about the system, he eventually joins them. Initially it seems merely entertaining, but they quickly discover that the game harbors deeper mysteries.