Japanese women are fed up with a longstanding Valentine’s Day custom requiring them to give chocolates to men without getting any in return.

According to an Internet survey, 70 percent of working women said they would be happy if there was no tradition of giving “obligatory chocolates” to their boyfriends or colleagues.

Nearly 60 percent said they felt unhappy as Valentine’s Day approached, citing the cost and time it takes to shop for the gifts, which are finely calculated to express just the right emotions toward a boss, a colleague or a true boyfriend.

The custom has grown into a sweet 50 billion yen ($424.6 million) market for Japan’s chocolate makers, some of whom rake in 20 to 30 percent of annual profits in a few short weeks.

Confectionary maker Morozoff Ltd. is widely credited with having introduced Valentine’s Day to Japan with a 1936 advertisement for chocolates, but it wasn’t until two decades later that Mary Chocolate Co. Ltd. used the day to promote chocolate sales.

“Our then-president admired how American women could express their feelings to men, and thought it would be good if Japanese women could do the same,” said Yoko Usami, a spokeswoman for Mary Chocolate.

A month later, on what is known as “White Day”, men are supposed to return the favor, usually by giving sweets - a task that they too are far from happy with, the survey found.

Fifty percent of men said shopping for a return present was bothersome, and they don’t like to be compared with others.

“Certainly things have now changed so women can freely express their affection, so the Valentine’s Day custom isn’t essential,” Usami said.

“But it allows people to acknowledge their own feelings, so I think it’s still nice to have.”

In a reflection of the changing times, perhaps, retailers say that women are now becoming much more likely to buy pricey chocolates costing up to $200 a box as a special treat - for themselves.