There is something really amazing in Japan, and I believe it is what we could call "trust" (or may be laziness!). For example in many places you can book without paying in advance (hotels, car rentals...), you can shop and pay later (it may not work everywhere though, and this also happens elsewhere)... Yet there's something like Japan got stucked in the 50's or the 60's. And what I love most it's when it comes to fresh vegetables and fruit shopping!
It is not unusual in the country to see stands by the road with freshly picked fruits and vegetables and no one there. It's not that it is closed... There is a box someplace: you pick-up what pleases you and put the money in the box. The deal is simple: super fresh resources for a super price!
I have the chance to have such a system on my way to the lab, close to Higashi Koganei station in Tokyo. When there are crops on the shelf there is a red flag floating and you just have to help yourself. Depending on the season they have daikon, cabbage, cucumber, potatoes, etc... Usually for 100yen. It's grown on the plot behind, and they use no chemical or whatsoever. It's fresh, natural and local! You just have to be quick to catch something, first in first served!