Durarara!! (デュラララ!!) is the first light novel of the series. It was released in the U.S. as part of the Yen On imprint.
The first light novel contains the first story arc, the Dollars/Mika Harima arc, and was adapted into the first four volumes of the Durarara!! manga and the first twelve episodes of the first season of the anime.
Synopsis
Mikado Ryuugamine, a high school boy looking for the extraordinary, moves to Ikebukuro, Tokyo, at the invitation of a childhood friend. Celty Sturluson, an Irish dullahan, rides the streets of Ikebukuro on a silent, pitch-black motorcycle, searching for her missing head. An information broker watches the people and scenes surrounding him with interest. A girl with a scar on her neck is running from something. Undocumented immigrants are going missing while the group trafficking them has ties to higher figures. A mysterious gang called the Dollars is the subject of countless rumors around the city. All of these stories come together in a few days in Ikebukuro.