Durarara!!

From Asaction

A mild-mannered kid moves to the big city and encounters the most dangerous people in Ikebukuro. Hijinks ensue. There's Shizuo, who has rage issues and is hot; Izaya, a sneaky information broker and the frequent target of Shizuo's rage; Celty, a headless Irish dullahan; Shinra, a sketchy doctor and Celty's handler; Simon, a black Russian guy; and a internet gang called the Dollars.