Ikebukuro, Tokyo. Mikado Ryugamine is a young man who yearns for the city like no other. At the invitation of his childhood friend, Masaomi Kida, he leaves his hometown and enters Raira Academy in Ikebukuro. Masaomi warns Mikado about some dangerous people in Ikebukuro to watch out for. There are two in particular: the brawling champion Shizuo Heiwajima and hobbyist information broker Izaya Orihara; And also the mysterious organization of unknown origin known as the "Dollars." On his first day out in the city, Mikado sees a jet-black motorcycle being driven by the fabled "Headless Rider." From then on, a series of random attacks and events begin to occur on the streets of Ikebukuro, and a group known as the Yellow Scarves arises as Ikebukuro begins to crumble!