One of our favorite things in Nasushiobara is the fruit market. Map Location
Most people think Japan is very expensive. But rural living, in a place like Tochigi, is actually quite cheap. The fruit market is a great example of this. Sometimes friends from Tokyo ask us to take them there to stock up on cheap fruit before returning.
We buy all our fruit and vegetables there. They have a wide variety of things, some local, some imported. Everything from apples to mangos, wasabi root to artichokes. (no durian). They also sell fruit gift boxes. In the back, there is a small supermarket. We don't buy so much in the supermarket, though we do buy quite a bit of our fish there.
This is one of the first places you should learn when you arrive in the area. Its better to get there early if you want the best choice, though it is good at any time of day.