あらすじ
One year after the SAO incident, Kirito is approached by Seijiro Kikuoka from Japan's Ministry of Internal Affairs and Communications Department "VR Division" with a rather peculiar request. That was an investigation on the "Death Gun" incident that occurred in the gun and steel filled VRMMO called Gun Gale Online (GGO).
あらすじはAniListより（英語）。