Nearly a year has passed since Mikado Ryuugamine moved to Ikebukuro, and the city has settled into a deceptive calm. Mikado recalls the words of information broker Izaya Orihara, who warned that even the most eventful metropolis eventually feels monotonous. That monotony is broken when Mikado’s old friend Miyoshi Yoshimune transfers to Raira Academy, injecting a restless energy back into daily life. Meanwhile, Shizuo Heiwajima, the famously volatile man with superhuman strength, finds himself wishing for better control over his anger. His boss, Tom Tanaka, suggests they go see a new popular movie starring Shizuo’s brother, Kasuka Heiwajima. The film, Bodyguard Case 2: Salaryman Ninja Guy, has sparked a citywide trend: people begin carrying attaché cases identical to the one featured in the movie. The headless dullahan Celty Sturluson, who works as an underworld courier, finds herself swamped with delivery requests for those very cases. Then a strange phenomenon begins to plague Ikebukuro: sudden, localized sandstorms referred to as “mists” that blind everyone in their vicinity. Taking advantage of these mists, an opportunistic thief starts snatching the popular attaché cases. The anonymous online chat that connects many of Ikebukuro’s residents buzzes with reports of both the thefts and the inexplicable tornado-like disturbances, yet no one can piece together why they are happening. The story follows the intersecting lives of Mikado, Masaomi Kida, Anri Sonohara, Celty, Shizuo, Izaya, and newcomer Yoshimune as the seemingly ordinary January days spiral into a web of secrets, old rivalries, and supernatural chaos.