Sometimes it's helpful, in cross-cultural contexts, to turn the question around and think about the assumptions behind it. How did European cities come to name the spaces in between the groups of buildings, rather than the blocks themselves? Any large building on a college campus, for instance, will have a dozen different corridors, but we don't have the expectation that the corridors will be named, only that the floors and rooms will be numbered in some logical fashion.

A long-winded way of saying that in Japan, the expectation is that the districts and blocks of a city will be numbered, assisting wayfinding in a different—but no more "unusual" manner—than we in the western world use. There's a famous short TED Talk about this.