Finding and recognizing a police station is something any tourist should know, even in a very safe country like Japan. Actually, in Japan the police boxes (called
kōban) can be very useful, especially for directions, whether you're lost, or you're just looking for an address (I'm sure you already know how difficult are the Japanese addresses) and they can be found in every neighborhood. These are not police stations in the Western sense, but smaller units, with duties involving close contact with the general public.
If you ever need their help, just remember that, on the Japanese maps, the police box is marked with an X, and look for small, usually two-storied buildings, marked with the word
KOBAN, written in Roman characters. Often, these building were designed to stand out, as this
kōban from Chiba, which resembles a huge owl...
Police box (koban), Chiba EXIF info:
Nikon D300
Lens: 18-70mm F/3.5-4.5G
Focal Length: 52mm
Aperture: F/4.5
Shutter Speed: 1/2500s
ISO Sensitivity: ISO 200