Showdown in the Wilderness
Kirito pretends to not understand Death Gun's answer, and Death Gun states that he will kill him, whether or not he is the real Kirito, before leaving. Kirito then has a flashback to his time in SAO, when he and several others battled Laughing Coffin, and notes that he killed two members during that battle. He then realizes that the player who confronted him was actually Death Gun. Sinon later meets up with him and senses that something is wrong, but before Kirito can confide in her, he is teleported to his next duel, which he wins. Eventually, both Kirito and Sinon have made it into the finals. While waiting for Kirito, Sinon begins to feel he is just like her. She becomes frustrated when Kirito calmly walks straight toward her position, not showing any signs of wanting to dodge her bullet. Sinon fires at him repeatedly, but misses, and she personally confronts him about it. Remembering the promise he made to Sinon, Kirito apologizes and sets the rules for a rematch: he would move away by ten meters, and they would start fighting once he throws a bullet to the ground. Despite Sinon's Hecate's one-hundred percent hit rate at such a range, Kirito shows his confidence in his abilities. When the rematch begins, Kirito is able to slice Sinon's bullet in half and hold her at the tip of his Photon Sword. Realizing that Kirito predicted the bullet path by watching her eyes, Sinon realizes that his strength goes beyond a virtual game and asks him what he is afraid of. He implies to her his experiences in SAO are not strength, but skill. He then asks her to surrender, since he doesn't want to defeat a girl. In anger, she does so, stating that next time would be different.
Aired 09/08/2014EP 6 - Showdown in the Wilderness

Sword Art Online II
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). "Players who are shot by a mysterious avatar with a jet black gun lose their lives even in the real world..." Failing to turn down Kikuoka's bizarre request, Kirito logs in to GGO even though he is not completely convinced that the virtual world could physically affect the real world.
Kirito wanders in an unfamiliar world in order to gain any clues about the "Death Gun." Then, a female sniper named Sinon who owns a gigantic "Hecate II" rifle extends Kirito a helping hand. With Sinon's help, Kirito decides to enter the "Bullet of Bullets," a large tournament to choose the most powerful gunner within the realm of GGO, in hopes to become the target of the "Death Gun" and make direct contact with the mysterious avatar.
(Source: Crunchyroll)