Here's how we livin' in Okinawa. By American standards, our apartment is incredibly small for two people but would be fine for a single. We were told that this is a "typical" Japanese apartment, and we haven't visited very many other locals or fellow JETs at home, so we're not sure how ours measures up. It's certainly inexpensive and conveniently located. :)
The Japanese have an apartment code just like we do. You know how we all know what things like "3 BDRM" mean? The Japanese all know what 3LDK means. Eric and I have a 2LDK, which means we have 2 tatami rooms and a single room called an LDK, or living/dining/kitchen. The tatami rooms have tatami mats (seen in upcoming photos) on the floor, and rooms are measured by how many standard-sized tatami mats can fit in that room. (They don't use square meters like we use square feet.) In general, tatami rooms are used as family rooms, bedrooms, and rooms to entertain guests.