Local Shops Have Great Prices Too
Daiso is actually a Hiroshima company that is now in Australia and other countries around Asia as well. However, none of the products are actually made in Japan. Of course it is fun to walk around and see all the cheap Chinese made products, but you can actually find most of the good things they have at other, local shops too that might be made just a little bit better and contribute to the Japanese economy.
I love to wander the back streets when I go to a Japanese city, there are usually some local shops selling a range of very dusty wares or if you can find an old style shopping street, you might be lucky enough to find actual artisan shops selling wares they have made themselves, on the premises. I found some particularly great artisan shops on the traditional streets of Matsumoto city- sandal makers, tatami mats and noren hanging screen shops, potters, roasted beans, and more... It was really fantastic to find
In Yamaguchi, the famous pottery town of Hagi also has a lot of artisan shops especially for pottery
Sugamo is an area of Tokyo where they have old markets and old shops selling local goods- this writer calls it "old timers Harajuku"
In Hiroshima, we have seen our old market areas completely destroyed in the advancement to a new and modern city. I had the opportunity to chat with an okonomiyaki shop owner who had been running her shop in an old place since WWII and she had so many interesting stories to tell.
Rebuilding and modernizing is fine, but they could at least offer these same shopkeepers preferential space in any new building- keeping their stories alive, they are a part of Japan's living history.
So my advice is of course to go to Daiso- there is one in every town in Japan- but don't ONLY shop at Daiso. Also, support the old, run-down yet completely charming shopping areas too. Otherwise they won't exist anymore and no one will be interested in visiting a Japan that is exactly the same as every other country in the world where you can buy the same low-quality goods as anywhere else.