The lives of its residents continue to intertwine in Ikebukuro, as though their destiny are predetermined. Mikado Ryuugamine is one step closer to his objective of living an adventurous life, and as a result, he goes deeper into Ikebukuro's darker side. After obtaining complete control of a former adversary, he wields his newfound authority as he sees fit, cleansing the Dollars from within to shape it into the perfect organization. This proves to be as difficult as it sounds, as Mikado now has to contend with unwanted outside influence, most notably a re-emerging and much-missed buddy. Meanwhile, Izaya Orihara still has some plans in his sleeve, albeit a rival information exchange center has proven to be a major stumbling block, lurking within everyone's reach.