Japan is turning silver. Right before “Respect For The Aged Day” this week, Tokyo announced that one out of every five citizens is now 70 years or older.

A declining birth-rate and a rising number of elderly is hitting Japan as hard as the 200 kilometers-per-hour serve of Naomi Osaka hits a tennis court. But if Japan is going to survive into a long-term future, it’s going to have do more than welcome in great multi-national tennis players.

When Osaka, born to a Haitian-American father and Japanese mother, became the first Japanese tennis player to win a Grand Slam singles tournament, citizens from Prime Minister Shinzo Abe on down rallied around their surprising new Japanese heroine. Even nationalistically tinged right-wing media celebrated her victory.

So, Japan loves her – and why not? She is legally “Japanese.”

However, she may not be for much longer.

Osaka was born in Japan on Oct. 16, 1997, but left when she was three. She speaks minimal Japanese and is learning to read it. While the victory of a mixed-race woman in Japan has once again raised the usual conversation about “what it means to be Japanese,” the real question many people should be asking is: “Why won’t Japan relax it’s stance on dual nationality? Should it?”

If it wants to keep the budding tennis star, it should. Next year, the national heroine turns 22. What happens if she doesn’t reject her American citizenship? Will she remain Japanese? Will the prime minister still be her fan?

Hazy laws and Kafkaesque conundrums

Japan only allows “mono citizenship.” According to related laws, all Japanese with dual nationality must choose to become solely Japanese nationals, or lose their passports, between the ages of 20 and 22.

Section 1 in Article 11 of the Nationality Law stipulates that if “a Japanese citizen acquires the nationality of a foreign country, that person loses Japanese nationality.” In other words, if a Japanese citizen obtains another nationality, even via international marriage, they must give up that nationality or their Japanese nationality within two years.

However, there is no penalty for non-disclosure. Moreover, the nationality law is not clear on what happens if you don’t choose by the time you are 22. Under current law, the Ministry of Justice can issue someone who fails to choose their passport a warning – then strip them of citizenship if they don’t make up their mind.

Temple University Professor Jeff Kingston, a historian and author of “Contemporary Japan”, explained the de facto way the law works for people like Osaka.

“The Japanese government generally averts its eyes from violations and doesn’t seem very keen about enforcing this,” he said.  That is just as well, as Japan had over 2.5 million foreign residents at the end of 2017, and many of them will marry Japanese nationals.

Kingston notes that even if there is lax enforcement, the existence of the law creates a chilling atmosphere. Many of those affected forced into a Kafkaesque existence, waiting for a punishment that may or may not ever come.

“The vast majority of dual nationals, and there are nearly 900,000… keep two passports and just play the game of selecting the one appropriate to the situation and try not to draw attention,” said Kingston. “They live in legal limbo but there is always the possibility that the 1985 nationality law could be used against you.”

In 2016, Ren Ho, an Upper House member of Japan’s parliament and the head of the Democratic Party of Japan at the time, came under vicious attack by right-wing media for her alleged dual nationality. She was born in Japan to a Taiwanese father and Japanese mother, and there was a huge uproar created about whether or not she had renounced her Taiwanese citizenship.

That hubbub only calmed down when she produced documents showing she had done so. Now, another hubbub is brewing.

‘Long and arduous fight’ begins

In March this year, eight former Japanese citizens, primarily residing in Europe, filed a lawsuit demanding the right to dual citizenship. They asserted that laws which force people to pick only one nationality are outdated, unconstitutional and not valid.

Hitoshi Nogawa, the lead plaintiff, gained Swiss citizenship in 2001, in order to be able to bid on defense-related public-work projects in his adopted homeland.  He was shocked when this resulted in him losing his Japanese nationality.

“Both my parents are Japanese, yet [due to this law] one day I lost my citizenship without any warning,” he said. “I felt paralyzed for weeks after finding out.”

The plaintiffs assert that Article 13 of the postwar constitution, guarantees them the right to the pursuit of happiness. They say that this pursuit is also grounded in Paragraph 2 of Article 22, which declares, “Freedom of all persons to move to a foreign country and to divest themselves of their nationality shall be inviolate.”

At a press conference held at the Foreign Correspondents Club of Japan in July, Nogawa explained how he gradually became aware of not only the profoundly negative impact of this law on his life, but the deleterious effects it had on the lives of dual-nationality youths as well.

“This will be a long and arduous fight,” he said. “But for the sake of children of Japan now and children born here in the future, I will fight. I think we will win.”

Battle against the ‘old farts’

Given the alarming slants on demographic graphs, the future of Japan may depend on the outcome. The UN Population Division warned as far back as 2000, that if Japan wished to maintain its working-age population at 1995 levels (87.2 million), that it would need 33.5 million immigrants by 2050.

Today, it’s not even close. The word “immigration” is virtually taboo.  And even former proponents of recognizing dual nationality in Japan’s ruling party, like Taro Kono, the Minister of Foreign Affairs, are avoiding the subject.

Author Kingston is scathing about the sentiment that underwrites the problem. It “..boils down to an identity issue related to the homogeneous nation myth, a myth nurtured by nationalists who are in denial about the growing diversity in Japanese society,” Kingston said.

There are some rays of hope. Now, mainstream newspapers like The Mainichi Shimbun are calling for Japan to join the international community and change the laws. And those directly affected are angry, if not quite outspoken.

“Hanako” – who spoke to Asia Times on condition of only using her first name, given the sensitivity of the issue – is a dual national in her late twenties, working for a Japanese financial firm. She is silently cheering on Nogawa, and paying close attention to his court case.

One of Hanako’s parents is from the United Kingdom and she holds two passports. “I love Japan and I grew up part of my life here, but I also love my other home and I don’t want to choose,” she said. “But honestly, if I was pushed to decide, after dealing with the rampant sexism and low-hanging glass ceiling for female workers in this country, I’d say ‘Sayonara Japan.’”

And she knows where to pin the blame. “If the old farts running this country don’t want diversity – screw them!” she said. “I’ll just shove off. And I doubt I’m alone.”

For a country with one of the lowest birth rates on earth, that could prove to a resounding warning.