With his handsome slim-fit suit, characteristic glossy shades, and a casual cigarette in mouth, word is that the remarkably strong Shizuo Heiwajima rules Ikebukoro's streets. When ordinary bartender Shizuo Nobusuma hears these rumors, he realizes he could make his own life a bit easier: as a con artist. Donning a blond wig and venturing into Ikebukuro assuming Shizuo's identity, the impostor is confident he is fooling everyone into doing his bidding. But as the district's residents either take pity or tease him before the actual Shizuo inevitably finds out, his luck plummets when he encounters Izaya Orihara—an information broker whose favorite activity in the world is messing with Shizuo.

With large windows adorning its spick-and-span halls, St. Morwald's Home for Children serves as a warm refuge for displaced orphans. For 10-year-old Aya, she is perfectly content living without a normal family, especially since she has everyone at the orphanage wrapped around her finger. However, to her dismay, she is one day selected by a peculiar couple, Bella Yaga and the Mandrake. Aya soon learns that she has, in fact, been adopted by a real witch who wanted her solely as an assistant and had not even considered being her foster mother. As if that was not enough, Aya is told the one rule she must obey at all times—never disturb the Mandrake. To win the hearts of this seemingly heartless witch and the grumpy Mandrake is no easy task; but unlike other children, Aya accepts this challenge without hesitation.

In spite of the mayhem that has been taking place in Ikebukuro, Shinra Kishitani and Celty Sturluson have decided to go on a short trip. Excited to finally be going out with the one he loves, the underground doctor makes it his priority to give Celty his undivided attention, even if it means rejecting phone calls from his good friend Izaya Orihara. However, despite his hopes of having a peaceful holiday, Ikebukuro's various residents continue trying to reach him. Furthermore, just as Shinra begins to enjoy reminiscing about old memories on a carriage ride together with his beloved, Celty starts to notice a strange presence...

One night, Mikado Ryuugamine accepts an invitation to Shinra Kishitani's apartment, eager to talk to Celty as quite some time has passed since the two last spoke. But, much to his astonishment, he finds that a large group of Ikebukuro's finest has gathered there for a hot pot party. Already confused with the current situation, Mikado is further surprised to see that his friend and fellow Raira Academy student Anri Sonohara is there as well. As the two decide to take a seat together, a few members of the group begin reminiscing over events from days past: Mikado recalls an adventure from his childhood with Masaomi Kida, Anri explains how she came to be friends with Mika Harima, and Shizuo Heiwajima tells of his first meeting with Tom Tanaka.