The quiet and happy life that Kirito painstakingly won after freeing Asuna from the nightmare of the nerve gear is interrupted by a government official, Seijiro Kikuoka, to whom Kirito owes a debt from the days of SAO. In the professional VRMMO GunGale Online — where players earn real money, one of the many new VRMMOs born from the free software package called The Seed — a mysterious player has appeared: Death Gun. Somehow he kills players in the virtual world, causing their deaths in the real world as well. And Kikuoka asks Kirito to look into this strange occurrence. Kirito converts his character from ALO to GGO and dives into the game — a harsh desert future where firearms reign supreme. And there he meets a reserved girl sniper who carries a deep, unhealed wound from her past.