Dear Alice,

What the heck are "lady's" discounts? I've only been in Japan for six months, but I've already been served a "lady's lunch" (free coffee and dessert); been to "ladies day" at the movies (almost half price); and went to Kyoto on a discounted package strictly for "ladies." I realize I'm cashing in, but I still find it shocking that a business would offer a lower price to one gender and not the other. My Japanese friends, even the guys, seem to think discounts for "ladies" are perfectly normal. But isn't it sex discrimination?

Andrea H., Toyama Prefecture

Dear Andrea,

You've been benefiting from a marketing strategy referred to as redei-su puran, a made-in-Japan amalgamation of the English words "lady's" (or ladies') and "plan." The term is most commonly written in katakana but it does get romanized, with the womanly word in all sorts of variations, with and without the apostrophe. Movie theaters, restaurants and hotels are all good places to find these special deals for dames, but I've also seen them at pachinko parlors, karaoke clubs and even gas stations.

According to Satoshi Akutsu, a professor of marketing at Hitotsubashi University's Graduate School of International Corporate Strategy in Tokyo, the ladies' plan came into vogue as a marketing tool about 25 years ago.

"The passage of the Equal Employment Opportunity Law in 1986 opened marketers' eyes to the purchasing power of working women," he told me. "Women in Japan still earn less than 70 percent of what men earn, but even so, many working women have more disposable income than their male counterparts. This is particularly true if they live at home with their parents, paying little or no rent."

Ladies' plans are effective because Japanese women tend to be price- sensitive as well as sophisticated about what constitutes good value, according to Akutsu. "Women are more likely than men to respond to sales and discounts, particularly those tailored to their specific needs."

Businesses that are traditionally male oriented, such as ramen shops and izakaya drinking establishments, often use ladies' plans to attract female customers. "Women who aren't accompanied by a man generally hesitate to enter these sorts of businesses," he said. "But it's much easier if the shop has a special offer for ladies, because it makes it clear that women are welcome."

Yes, but are they attracting women at the cost of alienating male customers? Hoping to figure that out, I reviewed a number of deals to determine just what the girls are getting that the guys are not.

In some cases, the product or service is what you might call "different but equal." A restaurant in my neighborhood, for example, offers a "ladies' lunch" at ¥100 less than the usual fare. The owner told me he saves enough on ingredients that he can charge less and still throw in the free coffee that attracts female customers. He'd happily serve the same lunch to men, if anyone asked, but so far no one has. "I think most guys would be embarrassed to ask for anything called 'ladies' lunch,' " he ventured.

In other cases, men are clearly getting the short end of the stick. The Brise Verte restaurant in the Prince Park Tower Hotel in Tokyo, for example, has a special "ladies lunch" in the month of July priced at ¥4,000. The menu states that men can have the same lunch, but only if they fork out an additional ¥500. And "ladies day" at the movies seems like a particularly egregious example, not only because the offer is so widespread — every Wednesday at many cinemas around the country — but also because the break for babes is so big: Women pay just ¥1,000 for a seat that sets a man back ¥1,800. So, why the heck don't the guys complain?

Actually some do, but it hasn't done much good. There are lively discussions on the Internet about dansei sabetsu (discrimination against men), largely griping about movie theaters. And in 2003, a man lodged an official complaint with the city of Kobe over gender-based movie discounts. But the city refused to intervene with theaters on pricing after its gender-equality panel determined that the man hadn't suffered any damage, and that being denied a discount to the movies doesn't constitute a violation of his human rights.

That may not be a legally defensible position. "It is a basic constitutional right not to be discriminated against on the basis of one's sex, if there is no rational reason for differentiating between the sexes," according to Hiroko Hayashi, a professor of law at Fukuoka University. "If a man was willing to file a law suit, there could be grounds for a favorable ruling. But because the discount on most of these ladies plans is just a few hundred yen, it's hard for men to see the benefit of waging an expensive legal battle."

To help me to a view from inside the courtroom, Hayashi offered to introduce me to Fukuko Sakamoto, a renowned lawyer who has waged numerous successful sex-discrimination suits. In 1966, for example, Sakamoto won a landmark victory against Sumitomo Cement that struck down kekkon taishoku sei, a requirement that women resign from the company when they got married.

I caught up with Sakamoto in a Shibuya high-rise just minutes before she was to give a speech on her half-century in practice. "The first thing I'd ask about is the basis for the discount," she said. "If the only criterion is gender, then yes, that does indeed sound like sexual discrimination."

The trouble, she suggested, is that many Japanese would not recognize 'ladies plans' as discrimination, and instead regard them as yugu (favorable treatment). "But by implying that women need protection or special treatment, these discounts perpetuate discrimination and run completely counter to our efforts to bring about equality of the sexes. Businesses should think beyond their own profit to the wider social implications of their practices, and find a better way to target female consumers."