There are several theories about the origin of White Day but the following theory is widely accepted. It is said that White Day was established by the National Candy Industry Cooperative Association as a sales promotion of candies in 1978.
In Japan, St. Valentine's Day is a day when a woman gives men chocolates. Chocolates of St. Valentine's Day are given not only for an important person but also for male colleagues and clients. And the chocolate without affection for St. Valentine's Day is called "Giri-choco[義理（ぎり）チョコ]"(Chocolate for a beloved someone is called "Honmei-choco[本命（ほんめい）チョコ]".).
Even if it is a Giri-choco, a man, who was given it from a woman, must commonly give the woman a gift in return on White Day because of maintaining their relationship.
Candies, cookies, white chocolates or marshmallows are mainly chosen as the gift of White Day. But now particularly, the gift for a lover is also selected from something other than confections such as jewelry and special dinner.