Tokyo (CNN)"Excuse me, are you hafu?" the taxi driver asked.
Anna, a woman of mixed Japanese and American heritage, was in a taxi en route to a party in Tokyo last year when she was asked that question, and says she had half expected it.
The Japanese word "hafu" -- or "half" in English -- refers to people who are ethnically half Japanese, and is now used more for multiethnic people in general in Japan.
Anna, who requested anonymity for privacy reasons, has a Japanese mother and a White American father, and spent her childhood in Japan, before moving to the US in her teens.
"I don't know how many hours I've spent telling my life story to strangers who want to fulfill their curiosity," says Anna. "It was getting to a point where I thought, Why do I need to share my biological background with someone I'm never going to meet again?"
Official figures paint Japan as an ethnically homogenous nation -- according to the 2018 census, 98% of the population is considered Japanese. People who look different, therefore, attract more attention than they would in a more ethnically diverse country such as the US.
In some cases, that's not a bad thing.
Many mixed heritage entertainers and sports stars are hugely popular in Japan. Well-known figures such as Vogue model Rina Fukushi and tennis star Naomi Osaka have given mixed heritage people more prominence in the public sphere in Japan, and globally.
For others, however, the apparent fascination with their heritage brings unwanted attention and can invite casual racism. Some who consider themselves Japanese say it leaves them feeling othered in their own country.
Mixed-race identity has a complex history in Japan.
Between 1639 and 1853, Japan closed its borders to foreign influence -- with the exception of Chinese and Dutch traders who came to the port cities of Yokohama and Nagasaki.
In those hubs, the derogatory term "ainoko" -- or "hybrid" in English -- was used to describe children born of a Japanese and foreign parent, according to Hyoue Okamura, a Japan-based independent scholar.
As Japan opened up and modernized during the Meiji era (1868 to 1912), it started cultivating its own brand of nationalism, promoting the country's racial homogeneity and superiority over other Asian nations. With the concept of Japanese supremacy came new terms to describe people of mixed race.
In the 1930s, the term "konketsuji" -- or "mixed-blood child" -- described the children of Japanese nationals who married locals in countries like China, Taiwan and Korea that Japan colonized. Those children faced discrimination as the government considered people from Japan's colonies as inferior to the Japanese.
Following Japan's defeat in WWII and during the American occupation (1945 to 1952), the term konketsuji applied to the children of American military personnel and Japanese women, and was considered a derogatory term. Politicians associated those children with Japan's defeat and painted them as a problem for society.
"Back then, there was a lot of debate over whether to assimilate or keep apart these children when they entered elementary school," says Lawrence Yoshitaka Shimoji, a sociologist at Ritsumeikan University in Japan.
A changing world
As Japan absorbed Western influences in the post-World War II years, perceptions changed.
European languages were seen as chic and exotic and Japan's fascination with Western movie stars grew.
Spying an opportunity, Japanese management companies started to promote local actors, dancers and singers of mixed heritage, says Okamura, the independent scholar.
By then, the derogatory term of konketsuji had given way to "hafu," a corruption of the word "half-caste". In 1973, its use was formalized in the 1973 edition of a dictionary called Kanazawa Shōzaburō's Kōjirin or "Wide Forest of Words," where it was listed as a synonym of konketsuji.
However, "hafu" didn't come with the same negative connotations as konketsuji. It was even used as a selling point to promote the girlband "Golden Hafu." The mixed-heritage quintet performed covers of Western pop songs such as 1962 US pop song "The Loco-motion," more famously covered by Kylie Minogue, and "Come, come to Hawaii!!! in Japanese.
The makeup and fashion industries picked up the trend, coining the term "hafu-gao" or "half-face" to represent an aspirational look that appeared half foreign. That look valued Japanese people with longer legs and defined facial features, including bigger eyes and taller noses, that gave them the impression of being non-Japanese, says Okamura.
Rather than unite the population, the buzz around "hafu" created an "us and them" mentality, says Okamura. Mixed heritage people who look more foreign than Japanese may be treated as foreigners, he added, even if they are Japanese nationals.
That's not always welcome.
The fascination with mixed heritage Japanese people can also be traced to the country's lack of immigration.
Last year, the country registered a record 2.93 million people as residents, according to Japan's Immigration Services Agency. That's still only around 2.3% of a population of 126 million -- much smaller than the 9% of foreign citizens residing in the United Kingdom and the 13.7% of US citizens who were born elsewhere.
In 2018, Japanese lawmakers approved a policy change proposed by Prime Minister Shinzo Abe to create new visa categories to allow an estimated 340,000 foreign workers to take both high-skilled and low-wage jobs in Japan over five years.
It represented a major shift in Japan's approach to immigration.
However, the change didn't go far enough, according to Jeff Kingston, a Japan expert from Temple University. He said the roles would be filled by migrant laborers who would be expected to leave Japan one day.
Despite the barriers, Japan's demographics are slowly changing. In 2019, one in 30 babies born in Japan had a non-Japanese parent compared to 1 out of 50 babies three decades ago, according to the Ministry of Health, Labor and Welfare.
While ethnic Ryukyuans, Japanese-Koreans, Japanese-Chinese and Japanese-Brazilians, among other mixed heritage people, are part of society often that diversity isn't reflected in the population figures.
Countries like America and Britain ask people to identify their ethnicity in surveys, but in Japan race, ethnicity, language, culture, class, and citizenship are conflated often leaving only options to identify either as "Japanese" or a "foreigner," according to a 2013 report published in Sociology Compass.
In 2019, the Japanese government changed the law to consider the Indigenous Ainu people as a minority. But there is no box to tick on census forms for people of mixed heritage, says Shimoji, from Ritsumeikan University. Japanese census forms do not, he says, ask respondents for their ethnic and racial backgrounds nor for the nationalities of their parents not registered in a family unit.
Japan's constitution stipulates that all citizens are equal under the law and granted fundamental human rights. At schools, teachers educate children on these topics, but the ideas have not properly taken root in the country, says Okamura, the independent scholar.
For instance, sometimes Japanese-Chinese or Japanese-Koreans, who are referred to as "invisible hafu" can face discrimination when they own up to their non-Japanese ethnic background, says Shimoji.
And others who have darker skin can receive unwanted attention.