Let's take a look at the Toki in the lower row: It sports a sugar content of 15 degree which - according to the small print on the price label - is very, very sweet (read "good" in the Japanese mind). Below 11 is "not sweet", the polite form for sour aka not good and to be avoided. 11 is normal, 12 sweet and anything over 13 is culinary heaven. At least in the mind of the standard Japanese consumer. They really have sweet teeth.
Of course this pursuit of sweetness has a drawback: Because everything sour is purged or fed to the livestock, it is almost impossible to find really sour apples, something I happen to like. The closest thing to my favorite Boskop Apple in Germany are imported Jazz from New Zealand. Unfortunately their season seems to be over. And I have to settle again with sweet apples.
On the other hand, the display of the sugar content is a very nice expression of the Japanese service attitude and sense of perfection. As seller you try the best you can to lull the costumer in a sense of security and peace of mind so that he or she happily and willingly spend a rather outrageous sum on your produce - without hesitation, second thoughts or regrets.