I'm a librarian who loves anime, manga, and reading a wide variety of genres.
Mikado is a naive high school student who just moved to Ikebukuro hoping for adventure. His friend Kida shows him around and tells him about people to avoid. Mikado sees an urban legend, the possibly headless motorcyclist, and meets Izaya, a scary guy who had planned on shaking down a couple suicidal young women for money.
I'm kind of glad I saw a bit of the anime first, even though it's already apparent that the two differ. All the scene changes would have been much more jarring, otherwise. I at least knew in advance that the series flits between a large number of characters, each with their own larger-than-life stories.
At this point, all I can say is that Izaya is scary-crazy, Mikado is a naive idiot, and Celty is looking for her head and may or may not be in a relationship with Shinra, the doctor. There are a lot of characters to follow.
The art style seems a little odd – kind of skewed. Or maybe the proportions are odd? Anyway, it's nothing I can't get used to. Visually, I prefer the anime, though.
(Original review posted on A Library Girl's Familiar Diversions.)