The destinies of those in Ikebukuro are undeniably linked. Mikado Ryuugamine craves excitement and is drawn to the city's shadows. His goal is to purge the Dollars from within and reshape it into a faultless organization, aided by a former foe he's won over. But obstacles arise when unexpected visitors, like an old friend, disrupt his plans. Meanwhile, Izaya Orihara schematically combats a rival intelligence agency in secret, fostering turmoil in the beloved city once again.