Never mind the smartphone, especially if you're not used to having one.

There are several English-language maps and atlases of Tokyo that are not available outside Japan but are readily available in bookstores in Tokyo.

Actually, this one, available from Amazon, looks good:

http://www.amazon.com/Tokyo-Walks-Wo...der_B00ATLB0DG

It contains neighborhood maps and narrative descriptions of the sights.

Don't worry too much about the lack of street names or addresses. In real life, people navigate by landmarks. They go to the nearest train or subway station and work from there. Advertisements for businesses typically contain an inset map showing how to get there from the nearest transit stop. Anyone who lives in Japan for any length of time becomes skilled at drawing maps.

Furthermore, everyone gets lost in Tokyo. It doesn't matter if they were born and grew up there; they can still get lost. Fortunately, Tokyo is one of the world's safest cities, and if you are obviously a foreign tourist, Japanese people will tend to think of you as a guest in their "home" and treat you kindly.

If nothing else, they can give you directions to the nearest train or subway station, and once you are in the station, there will be at least one map of the system in English.

Getting lost can actually be rather fun, because you can meet interesting people and see unexpected sights.