Sunny Yasuda can only vaguely remember his father. By the time he was born in Tokyo in 1975, his parents’ marriage was on the verge of collapse, and his Indian father soon returned to his homeland, leaving his Japanese mother on her own to raise their three children.

My place: Sunny Yasuda stands in front of the restaurant he manages in Tokyo on Monday. ALEX MARTIN

Yasuda cannot speak English, Hindi or any Indian languages, and as far as upbringing is concerned, is Japanese in every single aspect except for his appearance — his tanned complexion and South Asian features reflect his mixed background, something he recalls has always forced him to be an outsider when he was growing up.

And like so many other offspring of international relationships, Yasuda has experienced his share of dealing with Japan’s Nationality Law, which forbids retention of multiple citizenships to those over 22 — a rule the government cannot enforce due to technical difficulties, and an ambiguity that affects the lives and identity of many with similar backgrounds to Yasuda.

“I was the unlucky one,” Yasuda joked, when recalling how his older brother and sister both filed for Japanese nationality soon after Jan. 1, 1985, when the law was amended to allow Japanese nationality to children born in Japan to Japanese mothers.

Inheritance of citizenship was previously based on paternal lineage, and Yasuda and his siblings were all registered as Indian nationals upon birth.

“They had a choice, I didn’t,” Yasuda said, referring to the difference between him and his older brother and sister.

Those aged over 15 during the three years after the new law came into effect were considered eligible to apply without parental consent, and Yasuda’s siblings satisfied the requirement.

Yasuda, however, was 9 at the time, and needed both his father’s and mother’s written approval, which he could not obtain. His parents never officially filed for divorce — if they had, his mother’s consent would have been enough. His father had long since left the country and had effectively ceased contact with the family.

“Even if I had dual nationalities, I think I’d still have opted to be Japanese. I was told that you had to decide on one before you turned 20 or 21, and that’s what my brother and sister did,” he said.

Yasuda became a naturalized Japanese citizen when he was 17, soon after he attained permanent residency status. “We’re all Japanese now.”

“You know, you just ask yourself, ‘What’s the point?’ ” Yasuda said, recalling why he gave up his father’s nationality.

“I’d never been to India, and I only met my father once or twice when I was a kid. I heard he’s already passed away,” he said.

Still, Yasuda believes that people like himself, who were ignorant of the law or their cultural backgrounds due to the environment they grew up in, should be offered another chance.

“India’s in my blood. Yeah, I grew up in Japan, but it’s still a part of my roots. If I’d had the chance now, I would definitely want Indian nationality. It’ll give me new chances, new potentials, whether it be work-related or not,” he said, recalling how he had always been forced to be conscious of his racial heritage.

“Whatever job I took, wherever I went, I’d always start off as the ‘gaijin’ (foreigner),” said Yasuda, who has been working in bars and restaurants since finishing junior high school. He said that began to change when he was around 20.

“I think it was around then that I noticed a lot more foreigners in town. People began complimenting me for being a ‘half’ (of mixed descent), and I guess that sort of turned things around for me, changed my attitude, helped me feel positive,” he said, adding that if he ever has children, he would be sure to educate them about the culture of their grandfather’s country.

The number of international marriages in Japan has steadily increased over the years, peaking in 2006 at 44,701, accounting for 6.5 percent of all marriages that year according to health ministry statistics. The number of children born with multiple nationalities is believed to have been increasing accordingly, with unofficial government estimates predicting that there were 530,000 as of 2006.

Take the case of a 25-year-old Tokyo-based freelance Web and graphic designer born to a Japanese mother and British father. The man, who declined to be identified, decided to retain his dual nationality status even after he turned 22, when those with multiple nationalities are advised to officially give up one or the other.

The man initially only had British citizenship until his parents filed for his Japanese nationality following the 1985 amendment. He grew up receiving a Japanese education until high school, when he decided to transfer to a school in the U.K., eventually attending university there before returning to Japan.

“I’ve got two passports under two separate names. One has my Japanese name, the other my English name. How could authorities determine if it’s the same person?” the designer asked, adding that even if they did find out that he still kept both, there would be nothing they could do to force on him a decision — it would be tantamount to intervening in the internal affairs of the other nation.

He noted, however, that if he were forced to renounce either one of his nationalities, he would keep his British citizenship.

“Practically speaking, I could probably file for permanent residency in Japan relatively easily, having lived here for so long,” he said, adding that he felt being European would be more useful in his life.

“You know, I think this law is sort of like an urban legend,” he added, referring to the ambiguity of the age limit that some comply with but many are said to ignore, and the public’s lack of knowledge regarding the facts of the law.

“I’ve been paying my Japanese taxes, pension fees, I’ve got voting rights — I’d protest if authorities came to me now and took my Japanese nationality away,” he said, adding that he didn’t understand why Japan, with no mandatory military draft, disapproves of multiple nationalities.

This sentiment was echoed by a 30-year-old woman born in Japan to an American father and Japanese mother.

“I don’t understand the downside for Japan to allow dual nationalities. With a shrinking population and workforce, I would think they would want to encourage as many people as possible to live and work in Japan,” said the woman, a production specialist working for a Japanese game maker in San Francisco.

She, like her U.S.-born twin brother and sister, is a U.S. citizen, with permanent resident status in Japan. Her youngest brother, however, was born after 1985 and retains both nationalities.

“The real discrepancy (in the family) is between (my youngest brother) and me. We were both born in Japan to the same parents, but I was born 10 years earlier than him,” she said, explaining how her parents considered getting Japanese nationalities for their three older children after 1985, but in the end felt it was more hassle than it was worth.

The woman said that because she doesn’t have Japanese citizenship, she had to return to Nagoya, her home city, every few years to renew her re-entry permit, something her youngest brother doesn’t have to do.

“Another thing that bothers me recently is the right to vote,” she added. “As someone who’s spent the great majority of her life in Japan and has every other privilege as a Japanese person, I think it makes sense that I should have a voice on the decisions being made in government that would affect my life.”

In Mika Yuki’s case, however, it wasn’t the 1985 amendment that prompted her family to file for her Japanese nationality.

Her father originally came from Hong Kong. After marrying his Japanese wife and having fathered Yuki, he became a naturalized Japanese citizen in 1986, and on the same day, applied for her Japanese citizenship, passing on his newfound nationality to his daughter, who was born as a British national.

“I’ve never visited England in my life, and was never too conscious of my British nationality,” said Yuki, 26, who spent her high school and college years in the United States before returning to Japan to work at her father’s jewelry company in Tokyo.

She said that although she does consider Japan her home, she never strongly felt Japanese. Spending part of her youth in the U.S., she recalls how she always felt slightly out of place in both Japan and the U.S.

“I’ve thought about nationality and about its significance many times,” she said. “But in the end, it doesn’t really matter where I was born. I belong where my family is.”

Yuki said she was not even sure if she still retained her British citizenship. “I was told that eventually I would have to decide on one nationality over the other, but with the 1997 (handover) of Hong Kong to China, I’m not sure what’s happened to it,” she said.

The British Embassy in Tokyo said that those who haven’t applied for a British National (Overseas) nationality — a tailor-made nationality for Hong Kong residents with British Dependent Territories citizen status — by 1997 would have automatically lost their former British nationality.

Then there’s the case of a 27-year-old Japanese woman. In 2006, she filed marriage papers with her British husband, and the couple had a daughter the following year. The mother currently juggles her career with raising her 1-year-old.

The daughter is Japanese, something improbable before 1985. Her parents haven’t applied for her to obtain British citizenship just yet, although they plan on doing so soon — it could be done any time since the U.K. recognizes dual nationality.

It will be another 20 years before the girl might have to decide — if the current Nationality Law remains unchanged — on one nationality over the other. However, it is impossible to tell how she would perceive her identity when she reaches that age.

“In order for (my daughter) to embrace her international background as something to be proud of, I think it’s necessary that she be able to permanently keep her dual nationalities,” the mother said.