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.

“6 Months Later…We haven’t changed at all… or it seems….” Half a year after the turmoil that rocked the entire city of Ikebukuro— Peace has once again returned to the city and people are living each day normally. The high school students enjoy their days of youth as the strongest and most dangerous man of Ikebukuro works diligently. The informant plots a new scheme and the headless rider is pursued by the cops as she rides through the night…But soon this normal will be cut short by the abnormal. Slowly but surely, the unknown will seize the city and face an all new storm.