Sword Art Online: Phantom Bullet, Vol. 2 (manga)

Kirito has entered the new VRMMO Gun Gale Online in order to investigate the Death Gun incidents, only to discover his avatar is not exactly how he remembers it! He barely knows up from down in this new world, and he needs an ally. He may have found one in the mysterious female sniper Sinon, but she's got an agenda of her own...