Log Horizon (ログ・ホライズン Rogu Horaizun?) is a Japanese novel series by Mamare Touno. It was initially posted on the user-generated content site Shōsetsuka ni Narō in 2010 and subsequently published by Enterbrain since March 2011. The series follows the strategist Shiroe and the other players of the long-lived MMORPG Elder Tale after they find themselves whisked away into the game world following a game update. The novel has received four manga adaptations, with one based on the main story itself and the other three revolving around other characters in the series. An anime adaptation began airing on NHK Educational TV on October 5, 2013.
By its eleventh expansion pack, the massively multiplayer online role-playing game (MMORPG) Elder Tale (エルダー・テイル Erudā Teiru?) has become a global success, having a following of millions of players. However, during the release of its twelfth expansion pack: Novasphere Pioneers (ノウアスフィアの開墾 Nōasufia no Kaikon?), thirty thousand Japanese gamers who are all logged on at the time of the update, suddenly find themselves transported inside the game world and donning their in-game avatars. In the midst of the event, a socially awkward gamer called Shiroe along with his friends Naotsugu and Akatsuki decide to team up so that they may face this world which has now become their reality along with the challenges which lie ahead.