A year has passed since «Sword Art Online» (SAO) was cleared. Kirito is asked by Kikouka to investigate Gun Gale Online, specifically «Death Gun», a weapon which seemed to link deaths in the virtual reality (VR) world to those in the real world. Upon entering the game, Kirito meets Sinon who teaches him the ropes around the game. They both enter the Gun Gale Online tournament, Bullet of Bullets (BoB). Kirito displays his amazing skills although he is only a newcomer to the game. As the story continues, Kirito finds out that the mysterious deaths were linked to a red guild named Laughing Coffin in «SAO».