In Japan, Valentine's Day is known to be the day women gift chocolate to men.
When Valentine's Day culture was introduced in 1956, just after the World WarⅡ, chocolate was not the typical gift.
However, in late 1950's, confectionery companies started advertizing chocolate as gifts for Valentine's Day and chocolate gradually got so typical that currently 20% of chocolate in Japan is said to be consumed on the Valentine's Day.
This might be caused by the fact that chocolate was quite expensive and rare during the war.
These three types of chocolate below were developed depending on the relationship between a gift-giver and a gift-receiver.
"Honmei Choco" - Chocolate given to the one who the gift-giver has romantic feeling for.
"Giri Choco" - Chocolate meant to be given to guy friends, work colleagues, or bosses. Those gift-receivers are expected to gift back to the gift-giver on March 14th, so-called "White Day".
"Tomo Choco" - Chocolate gifted between female friends.