I think it is an intriguing subject to determine Japanese culture in terms of gifts. For I suppose the perception of “gift” itself is a little bit different from yours.
You may have heard of お中元 and お歳暮.http://gojapan.about.com/cs/traditioncu ... oseibo.htm
It is of a very complimentary nature. It usually acts as a lubricant in the Japanese society, however, it is true that it can be assumed a sort of “grading” of the person in some special cases. Since “apparent bribe” is tabooed in Japanese culture, giving “valuable things”, such as gold, doesn’t work. So our culture needs something suitable for special gifts; something very rare and expensive, good enough to express their “courtesy”, but never to be accepted as a monetary bribe, which means, the consumable is ideal. Also, in the context of feudalism history, the only things that people of low position could offer to the higher were agricultural products. They don't tell that you are showing off your wealth. It can express your modesty at the same time.
Thus, the expensive fruits have got a symbolic meaning. In addition to that, they are delicious. By delicious, I mean sweet. They usually have extremely high sugar content compared to normal products. “Sweetness” is a simple quality that anyone can feel even if the person is not familiar with the evaluation of delicate quality like wine. They look beautiful in a special gift box, smell definitely different from normal ones, and very sweet. They fulfill a perfect role in the traditional Japanese society in the conventional value.
Very interesting. Just my two cents, though.