Deputy Prime Minister and Finance Minister Taro Aso once declared in 2005, to the considerable derision of many of his countrymen, that Japan was the only country in the world with "one culture, one civilisation, one language and one ethnic group".
The Communications Minister at the time, Mr Aso was, ironically, speaking at the opening of a museum which featured exhibits showing how other Asian cultures have influenced Japan's own cultural heritage.
Japan's real or imagined cultural homogeneity - foreigners make up 1.6 per cent of the population - is often cited by analysts as one reason for the unwillingness of its people to accept immigrants.
A similar sentiment appears to be behind award-winning author Ayako Sono's Feb 11 column in which she suggested that foreigners can help ease the labour crunch in Japan's nursing sector but that they should be housed in communities segregated by race and apart from mainstream Japanese society to avoid problems.
The 83-year-old writer noted that apartheid-era South Africa managed to keep the social peace by separating its population into communities based on skin colour. Her anachronistic views, not surprisingly, raised howls of protest at home and abroad.
However, while most Japanese do not share Sono's sentiments, many are still unnerved at the idea of new immigrants living in their midst. A common reaction is: "Crime will go up." The question is, can Japan afford to hold such attitudes towards immigration, at a time when it is facing a demographic crisis that has severe economic implications?
Analysts predict that Japan's 127-million population could fall by a third in 50 years' time due to its low fertility rate. Citizens aged 65 and older could eventually account for 40 per cent of the people. This could slow the economy.
Yet a bold immigration policy is the one thing that remains conspicuously absent from Prime Minister Shinzo Abe's so-called Abenomics growth strategies. His government still clings to "back-door" measures such as a scheme that lets farms and small factories recruit workers from abroad in the guise of "technical trainees". Bilateral treaties with some Asean nations let in limited numbers of foreigners as nursing care workers.
Knowing the negative reaction of Japanese to the word "immigrant", Mr Abe has taken pains to stress that such measures do not constitute "immigration policy".
But despite these steps, there is an acute labour shortage in many sectors, not least in construction, which has had to halt many projects in disaster-hit areas.
The need to bring in foreigners to help build roads, stadiums and other infrastructure for the 2020 Olympics in Tokyo presented a golden chance for Mr Abe to open up his country wider to foreigners. Instead, construction firms were told to recruit through the technical trainee scheme.
Mr Abe extended the visa for such "trainees" from three to five years to allow construction firms to meet their Olympic deadline with minimal disruption. The message was clear: "While we want foreigners to work for us, we don't want them to stay forever."
A survey by the Yomiuri Shimbun daily last year showed that while 37 per cent of Japanese thought their country could accept more foreign workers, only 10 per cent of those said manual workers should be allowed.
The right-wing quarters of Japanese society that support Mr Abe are also against immigration.
Also, immigration policy flops in Germany and other European nations in recent years, resulting in social unrest due to the failure of immigrants to integrate into their host nations' societies, have not gone unnoticed by the Japanese. Hence, their rejection of any solution to the population shrinkage which calls for an open-door policy towards immigrants.
But former Tokyo Immigration Bureau chief Hidenori Sakanaka believes only immigration can save Japan. In a proposal last year, he suggested Japan should bring in 10 million immigrants over 50 years, or 200,000 a year, to make up for the projected population shortfall.
But bureaucrats and politicians would not hear him out, he said.
The respected Toyo Keizai economic weekly, in a December issue, pointed to the same elements as obstacles to a more open immigration policy. "The government loosened rules for foreign construction workers for the 2020 Olympics. But progress overall is slow. To care for old people, we need more nursing care workers. But there remains strong opposition among bureaucrats and politicians," it said.
Mr Abe's oft-repeated solution is to get more women and senior citizens into the workforce, but this is unworkable without better social infrastructure to help working mothers care for infant children, and the full cooperation of employers with regard to giving more jobs to retirees.
Time is not on Mr Abe's side.
While welcoming foreigners to live and work long term in Japan will not be a popular decision, it is one that any responsible Japanese politician will have to give serious thought to. In this regard, the recent xenophobic rant by author Sono not only smears Japan's otherwise-sterling international reputation, but also hinders Mr Abe in his decision-making.