The young woman is polite, friendly, and happy to explain why she and her husband have chosen not to have children as long as she doesn't have to give her name. In a country that cherishes babies, the stigma of intentional childlessness is sometimes too great to bear.
"We haven't actually told our parents that we have no plans for children," she admits, explaining that she and her husband prefer to play golf and operate as a twosome. "They think we can't. They might panic if they knew."
They are called No Kids couples (NOKS), and the growing number of NOKS runs against the grain in a country that views its shrinking population as a pending national crisis.
The average number of births per birthing-age woman in the country dropped to 1.36 in 2000, down from 1.91 in 1975, and well below the 2.08 figure required to sustain the country's current population.
The government foresees problems over the next 50 years as the number of senior citizens approaches 35 percent of the population. And the shrinking labor pool is a concern.
A driving force behind the trend seems to be the desire for personal satisfaction outside parenthood. It's something the Japanese government has monitored with some discomfort.
"People's awareness in terms of the role of the family is changing, putting more emphasis on being 'couple-centered' and 'peace-of-mind-centered,' rather than child-centered," concludes a 1997 report by the Japanese Ministry of Labor.
The Japanese are hardly alone in this shift. Throughout the US and Europe, growing numbers of couples have opted in recent decades for a freer-wheeling, more economically prosperous, double-income no-kid (DINK) lifestyle.
"There are definitely more DINKs in Japan today," says Sakie Fukushima, an executive with Korn/Ferry International in Tokyo. But she adds, "This is still a very limited group."
For that small but growing group, it remains difficult to share such a decision, especially with friends and family.
Perhaps that's one reason some Japanese women pour out their thoughts and feelings anonymously on a Japanese website for child-free couples called Noks Life.
"It may be that I'm strange, but since I got married I never thought that I wanted children," writes 32-year-old "Gomacchu." "I enjoy the life with my husband, just the two of us."
Her mother insists on children, but she doesn't give a convincing reason, Gomacchu writes. "The more I think about it, the more I don't understand."
"In Japan, there's a strong feeling that you don't have children for yourself but you have them for your parents," says Akira Takemoto, assistant professor of Japanese language and literature at Whitman College in Walla Walla, Washington. "That's why it's difficult for young adults to make that choice and to be vocal about that choice."
One woman writes of how embarrassed she feels when her mother-in-law speaks critically of another childless couple in their neighborhood. Another woman says she has lost friends because she doesn't have children.
Yet, some say the opposite. The young woman who hasn't told her parents that childlessness was a choice says she and her husband have gained a new group of friends.
"Now that we've made this decision, we've found others like us," she says. "They, too, have chosen to enjoy their lives themselves."
"The social attitude is changing," says Minako Misawa, a writer and producer for Japanese national television, who has a 2-year-old daughter.
"It has become more acceptable not to have children just recently, I would say in the past five or six years."
Nonetheless, for the Japanese, "it's like violating the meaning of marriage not to have children," says Leonard Schoppa, associate professor of politics at the University of Virginia in Charlottesville. And yet, he adds, not too long ago in Japan it was considered a negative to reach the age of 30 without marrying, a notion that has dissolved in recent years.
It could be that the taboo against childless couples, says Professor Schoppa, will soon be gone as well.