Although peace has finally returned to Ikebukuro, many of the odd occurrences have become common sights around the city. One such case is the police's constant pursuit of Celty Sturluson, the Headless Rider. Moreover, someone has placed a large bounty on her, igniting the motivation of gang members all over to begin searching for the supernatural creature as well. Meanwhile, Mikado Ryuugamine is approached by Aoba Kuronuma, a mysterious underclassman with unknown intentions, who reveals that he knows Mikado's true identity. But Ikebukuro's state of tranquility is short-lived, as a new threat appears in the form of a murderer who goes by the pseudonym "Hollywood," known for wearing a different mask each time they commit a crime. As the various events taking place prove to be connected yet again, Ikebukuro is thrown into another conflict that threatens to engulf the entire city in chaos. 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 (or plans) 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.