Durarara!!

is a Japanese light novel series written by Ryogo Narita, with illustrations by Yasuda Suzuhito. The series began publication on April 10, 2004 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Durarara!! and Durarara!! SH have been licensed for an english release by Yen Press under their Yen On Imprint.

Synopsis
In Tokyo's downtown district of Ikebukuro, amidst many strange rumors and warnings of anonymous gangs and dangerous occupants, one urban legend stands out above the rest—the existence of a headless "Black Rider" who is said to be seen driving a jet-black motorcycle through the city streets.

Mikado Ryuugamine has always longed for the excitement of the city life, and an invitation from a childhood friend convinces him to move to Tokyo. Witnessing the Black Rider on his first day in the city, his wishes already seem to have been granted. But as supernatural events begin to occur, ordinary citizens like himself, along with Ikebukuro's most colorful inhabitants, are mixed up in the commotion breaking out in their city.

Durarara!!
An anime adaptation of the first three volumes of the light novel aired for 24 episodes between January 8, 2010 and June 25, 2010.

Durarara!! X2 Shou
An anime adaptation of volumes 4 - 6 of the light novel. Aired for 12 episodes between January 10, 2015 and March 28, 2015.

Durarara!! X2 Ten
An anime adaptation of volumes 7 - 10 of the light novel. Aired for 12 episodes between July 4, 2015 and September 26, 2015.

Durarara!! X2 Ketsu
An anime adaptation of volumes 11 - 13 of the light novel. Aired for 12 episodes between January 9, 2016 and March 26, 2016.