Ikebukuro (池袋), is a commercial and entertainment district of Tokyo and the largest city in Toshima ward.

Ikebukuro is the general location setting of Durarara!! and is home to its protagonists. It is also home to many myths, including the headless Black Rider who rides a noiseless pitch-black motorcycle; strange characters, including an underground doctor in love with a monster, a sushi-selling Afro-Russian, an emotionally detached serial slasher and movie star, and a serial killer who wears bizarre movie costumes; and the infamous "color gangs" that fight for territory in the city. A new gang has appeared recently: a colorless gang called the Dollars growing in size and influence whose leader is a mystery. Motorcycle gangs, yakuza, and the Russian mob all play a role in the city where the police are just as threatening as the criminals. The kidnapping of teens and undocumented immigrants for human experimentation occurs regularly, and street fights often break out between gangs or an information broker and an insanely strong debt collector in a bartender's uniform. High school students make friends and fall in love. Violence erupts and escalates in the city as the various sides pursue their ambitions, unaware of being pieces on a chessboard being moved toward a larger goal.