Because of the vantage point he chose (not too high up, but now too low either), Sato says that he was able to gain an almost "horizontal" view of Tokyo. The effect is that, rather than looking down with a bird's eye view, or looking up from the street, with the buildings towering above, the viewer can feel that he is neither tourist nor spectator but someone truly living and breathing in the city. That Sato's choice of perch was the fire escape, which tends to be at the rear of buildings, facing the "backstreets", helps to make the photographs in this book extraordinarily intimate, and that is not a word often associated with the most populous metropolis in the world.
Please note that the captions, Sato's afterword, as well as an essay about the work by Yoshiharu Tsukamoto, a professor of architecture, are all translated into English in the book.
In addition to the images of the book itself (linked below), you can also see a sampling of photographs from the book at Sato's web site.