Japan, Tokyo. The district of Ikebukuro is a strange place where a curious urban legend persists: a headless biker woman is said to roam the streets of the district, perched on a motorcycle without headlights or lights.

Mikado Ryûgamine is a young high-school student who has recently moved to the district on the advice of his old friend, Masaomi Kida. But as he discovers Ikebukuro and its urban legends, he is surprised by Kida's attitude when someone mentions to him the gang wars that raged in the neighborhood a year or so ago. A past that is all the more worrying as a new gang, dubbed "Dollars", seems to be developing very rapidly in the neighborhood.