Log Horizon (Light Novel)

The Log Horizon light novel series was first released in web format by Mamare Touno. Seven volumes have subsequently been published, with an eighth to be released on September 29, 2014. Yen Press has licensed the series for its light novel publishing section, Yen On. The first volume is slated for a March 2015 release.

The Catastrophe arc
On May 3, 2018, thirty thousand Japanese players of the popular MMORPG Elder Tale found themselves trapped in -- or a world startlingly similar to -- the game. A reclusive yet well-known Enchanter, Shiroe, is among them. After quickly contacting his long-time in-game friend Naotsugu, a Guardian, the two of them wander about the streets of Akihabara, their player city. While assessing the situation, they are found by Shiroe's friends, a bubbly female Cleric named Maryelle and the relatively more composed Henrietta, whom they exchange information with. After some days of exploration, they meet yet another of Shiroe's companions, a stoic Assassin named Akatsuki. "He" turns out to be a "she," trapped in her initially-male avatar, saved from her plight thanks to Shiroe's possession of a rare appearance-changing potion. Because of this, she dedicates herself to him as her "ninja," and together, the three work on honing their fighting skills as they witness the deteriorating situation in the city.

Route 43 arc
This arc covers the material found in Log Horizon 8: The Sparrows Stretch Their Wings.

Dragonhowl Mountains arc
This arc covers the material found in Log Horizon 9: Kanami, Go East!.

Resources
There are some notable differences between the web and novel versions. As of the moment, the web version is still being updated. However, translation projects for the novels appear to be focused on the published versions.

Official Sites:
 * mamare.net: Mamare's official site (currently down)
 * Web novel: A site where Mamare publishes the initial version of the Log Horizon chapters. (Currently on volume 8.)

Translation Projects:
 * skythewood: Fastest updates and most recent chapters. Currently on Volume 7's web novel, awaiting a published Chinese copy of volume 7. Because Yen Press has licensed the light novel, he will no longer be translating them.
 * Baka-Tsuki: Uses skythewood's translations, with minor edits. They will be taking down the translations once Yen Press publishes the first volume.
 * iforgot: An independent project starting from Volume 1. More sporadic updates.