While I'm on a culture jag, I thought I'd tell you about a holiday we have in Japan called White Day.
Much like the hanakotoba, in Japan around Valentine's Day, we have a special language for chocolate gifts given. On Valentine's Day, only girls give out chocolates to their friends or generally to men that they know/work with/like. Dark chocolate is the most popular. There are specific instructions for the type/amount and whom you should give chocolates to among adults, but for people my age, the general rule is to give chocolates to all of your male friends and acquaintances. If a really expensive or hand-made chocolate gift is given, this is the signal that a girl likes you and is asking you to be her boyfriend. Valentine's Day is seen as an excuse to be a bit bolder than normal and hint to a boy that he should ask you out, if you usually wouldn't do this sort of thing. Then she has to wait the long month for White Day.
White Day takes place on March 14, exactly one month after Valentine's Day. The thinking is that all gifts given out must be returned at least three times better/more valuable by the boys who received chocolate, so usually girls give out chocolates to everybody to make sure they get a big haul. White Day is called as such originally since white is a symbol of purity and a "blank slate", signifying new beginnings, for example, staring a new relationship. Generally, chocolate or gifts are white too, but not everybody does this. If no gift is returned, this means that the man considers himself to be in too high a position to take note of the girl, and is generally quite rude. A gift of equal value signifies that the guy is doing the bare-bones requirement out of politeness only, and means that he's not interested or no longer wants to go out with you. The general three-fold rule gift is the most common, and depending on the value of the original gift, signifies that everything is A-OK and/or you wish to accept the offer and begin a relationship. Obviously, it's all very romantic and girls love it. What girls do not love, however, is when the white gift is not something like white chocolate or white flowers. A popular prank among guys my age is to give white panties to the girl, something "romantic" among adults, but hilarious among high-schoolers, who get to watch her open up the gift and unwrap panties in front of everybody when there is no actual relationship to warrant that. It's funny, I don't care what anybody says. It's better than receiving nothing at all right?
Anyway, among my close friends and people from Japan I know, we observe this tradition here, and maybe you'd find it interesting and want to start it among your own group of friends!