Elder Tales is an online fantasy RPG that has become popular worldwide. But when its twelfth expansion package, "Cultivate the Noosphere," is installed, thirty thousand players in Japan are trapped inside. Among them is grad student Shiroe, who isn't very good at interacting with others. But to survive in a world full of monsters, he forms a guild called "Log Horizon" with an eclectic group of other players.
After putting an end to the SAO incident in the year 2022 and rescuing Asuna in ALfheim Online (ALO), Kazuto Kirigaya finally returned to the real world to resume a normal life with his friends once more. However when a string of deaths begin occurring in connection to a virtual reality game called "Gun Gale Online" (GGO), Kikuoka Seijiro of the Ministry of Internal Affairs enlists Kazuto to once again don his character "Kirito" and enter the virtual world to investigate the cause of the deaths. While meeting new allies, Kirito may be faced with his most dangerous challenge yet a player known only as "Death Gun" with the ability to kill a person in the real world by killing their virtual avatar.