or,

"The compulsory nature of Valentin day!"

"In Japan, in 1960, Morinaga, one of the biggest Japanese confectionery companies, originated the present custom that only women may give chocolates to men. In particular, office ladies will give chocolate to their co-workers.

One month later, in March 14, there is the White Day, created by the Japanese National Confectionery Industry Association as a "reply day", where men are expected to return the favour to those who gave them chocolates on Valentine's Day.

Unlike western countries, gifts such as candies, flowers, or dinner dates are uncommon. It has become an obligation for many women to give chocolates to all male co-workers. A man's popularity can be measured for how many chocolate they receive on that day; the amount of chocolate received is a touchy issue for men, and they will only comment on it after getting assurances that the amount will not be made public. This is known as giri-choko (義理チョコ), from the words giri ("obligation") and choko, ("chocolate"), with unpopular co-workers receiving only "ultra-obligatory" chō-giri choko cheap chocolate. This contrasts with honmei-choko (本命チョコ, Favorite chocolate); chocolate given to a loved one. Friends, especially girls, may exchange chocolate referred to as tomo-choko (友チョコ); from tomo meaning "friend"."

(wikipedia)