Ive lived in Japan for 6 years
If you want modern stuff, then your best bet would be to stay in the urban areas.
Depending on where you are in Japan, the lifestyle changes alot.
Also there are some US Air Bases in japan that accommodate civilians. I lived in an Apartment that was a mile away from the High school, and Elementary School. They were also american owned.
Also the climate differs drastically depending on your location
For example, itll be hot in Okinawa but in Misawa which is in the northern end of Japan, I got a massive amount of snow. So much that between December and February there was atleast 2-3 inches of snow on the ground at all times.
Also if you like Sushi, and dont like Grocery store sushi, then this might be your saving grace.