Kazuto Kirigaya has essentially re-entered the real world a year after leaving Sword Art Online. His tranquility is short-lived, though, as instances continue to happen in the online game Gun Gale Online, where a player by the moniker of Death Gun appears to be shooting real-world citizens to death.
Kazuto takes his identity of Kirito once more as he registers with Gun Gale Online to stop the murderer after being asked by a state official for assistance in solving the crimes. Just beginning the game, Kirito encounters Sinon, a highly skilled sharpshooter who is plagued by her horrific background. She soon becomes involved in the hunt for Death Gun, and the two of them participate in the Bullet of Bullets, a competition where their adversary is guaranteed to appear.
Since Kirito and Sinon are unclear of Death Gun's real abilities, they attempt to stop him before he can take any more lives. But things don't always go as planned because they are still plagued by the effects of the past. Kirito risks his life once more in the virtual world in a game where one of them could very easily be the next victim.
