The mystery of Tokyo’s street address system has been unravelled by Stephen Banker, a fellow recent tour traveler to Morocco and, coincidentally, a sojourner in Tokyo during the Forseter Family trip there in 1991.
Pardon the pun, but this is the best type of “crowd sourcing.” Here’s Steve’s explanation:
“It happens I was living in Tokyo when you visited in 1991 (I was there for two years), and I learned my way around. Yes, the addresses can be mystifying, but I think I can demystify it for you:
“You probably already know that there are a number of ‘kus’ in Tokyo (17?). We might think of them as boroughs. Within each ku there are neighborhoods, each having a name and distinct borders. Each neighborhood is further broken down into districts of only a few blocks each. These districts are numbered.
“Within each numbered district, each block has a number. Each building on the block has a number, which you point out are NOT in geographic (numerical) order. I was told they are in chronological order.
“As a block was developed, the formerly empty lot was given the next number not previously used. So every address has the ku, the neighborhood and three numbers: the district, the block and the building number.
“For example, my address was 4-1-12 Minami Azabu (the neighborhood), Minato-ku, Tokyo.
“(The system was ) not developed to confuse invaders, but certainly effective.
“Maps are essential. In fact, many people (at least the ex-pats) have personal cards with a small map on the back to show the location of their home.
“But in one sense this address system of sequential narrowing-down is quite effective—especially when compared with the numbering system of Manhattan’s avenues, which are indeed numerically consecutive, but absolutely no help in finding the cross street (unless you know the secret code and do the math).
“BTW, the Imperial Palace is at the center of the maze that is Tokyo, which I understand WAS intended to deter invaders.”
When I commented to Steve that getting around Tokyo was difficult even when taking a taxi—one time we showed our taxi driver a piece of paper with the address we were going to only to have him shake his head. Seems he could not read, Steve responded, “That surprises me, as the literacy rate is extremely high. Many/most also can read English, but not speak it or understand spoken English. Some taxi drivers just want nothing to do with ‘gaijin’ (a pejorative word for foreigners), as they’re more trouble than they’re worth.”