Valentines day in Japan is different to the rest of the world where ladies traditionally give chocolate to the lads - and the lads would give chocolates back to the ladies on "White Day" next month on March 14th.
The Japanese Wiki entry for Valentines Day in Japan differs from the English version as to how it became that Valentines day was to be a day where only women would give chocolates.
Even if women don't particularly have anybody who they have the hots for, many feel obligated to give chocolates to their superiors or male co-workers - this type of chocolate is called "Giri Choco" [義理チョコ] or "obligatory chocolate."
There are other types of chocolate marketing terms such as "Tomo Choco" [友チョコ] where girls would give chocolate to their best female friends. Then there is the term [自分チョコ] where folks buy chocolate for themselves.
As mentioned above, the Japanese came up with "White Day" [ホワイトデー] which takes place on the 14th of March. The day gives men a chance to give back white chocolates to the ladies who he received chocolates from - but! He has to make sure that what he gives costs more than what he received. Its hard to tell how much received chocolate costs so he ends up spending a bomb.
If the lady then receives chocolate from a man that was cheaper than what she gave, this can be seen as a case of sexual harassment!
Given all the chocolate marketing terms, White Day and a risk of sexual harassment if one does not spend enough, its no wonder why many folks think that Japanese Valentines day is a conspiracy by the chocolate industry ^^;
20% of annual chocolate consumption in Japan takes place over the Valentines day period.
Ah, there is actually a "Orange Day" [オレンジデー] which takes place on the 14th of April.
Orange Day was introduced in 1994 and is a day where partners would give each other oranges to prove their love for each other - introduced as an excuse to sell more oranges ^^;