Despite a veneer of peace in Ikebukuro, peculiar happenings are now a regular part of city life. The Headless Rider, Celty Sturluson, remains the target of persistent police pursuit, while a gang of anonymous members is on the lookout for the prize that comes with her capture. Mikado Ryuugamine is once more disturbed from his tranquil lifestyle when a mysterious new student, Aoba Kuronuma, contacts him and exposes the truth about Mikado's persona. Unfortunately, this tranquility is short-lived as a killer nicknamed "Hollywood" materializes, recognized for putting on identifiable masks to hide their face every time they commit a crime. Ikebukuro is embroiled in yet another perplexing situation that has the potential to devastate the whole city as these events coincide.