Last time I was in a convenience store, I noticed a box of Dars chocolates with backwards writing on it. In every way, it looked like a regular box of this particular variety of chocolate. I couldn't understand what the point of the reverse writing was until I came across an article on Japan Marketing News.
Apparently, the reverse writing is an attempt to get Japanese men to buy Valentine's candy for Japanese women this year. Since the tradition has been for women to give men candy on February 14 and men to return the favor on March 14 ("White Day"), the candy companies want to encourage men to "reverse" the giving and give women chocolates on Valentine's Day.
It's probably a good ploy. Most of the Japanese women who I have spoken with about the White Day holiday say that the vast majority of men do not reciprocate for the Valentine's candy the women around them gave them. It'd probably be far better for sales if both men and women were on board for Valentine's Day. From a commercial point of view, White Day has generally been a bit of a failure.