TOKYO (AFP) - Emmanuel, Stephane, Henrik and James come from very different backgrounds, but they share the same painful experience of battling Japan's legal system - in vain - for access to their children after divorce.
Once married to Japanese women, they say they were prevented from contact with their children when their relationships disintegrated, sometimes even after court rulings in their favour.
Tough laws and patriarchal cultural norms that overwhelmingly see mothers granted sole custody after a divorce - 80 per cent of the time, according to official figures - mean that fathers rarely see their children again.
Frenchman Emmanuel de Fournas has spent years battling for access to his daughter after his Japanese ex-wife moved back to Japan.
Despite winning a court order in France and filing a case under the Hague Convention on the Civil Aspects of International Child Abduction in September 2014, he is still fighting for the right to see his daughter.
"I thought I could benefit from the clear rules of the Hague Convention, but... they aren't respected in Japan," he told AFP.
"I've lost everything, my savings, my job," he said tearfully.
His experience is not unusual.
Henrik Teton from Canada and James Cook from the United States have similar stories to tell.
"What kind of justice system is it if decisions are not implemented? There is room to do more and better," says Richard Yung, a French senator who came to Japan to plead the cases of several French parents.
Although Japan has signed the Hague Convention designed to prevent a parent from moving a child to another country and blocking access for the former partner, Tokyo demonstrates "a pattern of noncompliance" with the pact, according to the US State Department.
For foreign parents, most often fathers, "this poses major problems, because they have a different mentality and they can't comprehend losing custody or the right to visit their child", said Nahoko Amemiya, a lawyer for the Tokyo Public Law office.
Even when foreign parents win their case in a Japanese court, enforcement is patchy.
The State Department's 2018 report described "limitations" in Japanese law including requirements that "direct enforcement take place in the home and presence of the taking parent, that the child willingly leave the taking parent, and that the child face no risk of psychological harm".
With opinion divided on what causes the most trauma to children, the longer a child is separated from one parent, the more reluctant the authorities are to intervene, citing a "principle of continuity".
"It's not that Japanese courts favour the Japanese parent, it's that they favour the 'kidnapper'," who is living with the child, said John Gomez, founder of the group Kizuna, which advocates for parents separated from their children.
Japan's government defends its record, saying most of the 81 cases filed under the Hague Convention since 2014 have been settled.
"The majority of the cases in which we intervened have been resolved, but we are aware of six or seven where the return decision could not be implemented," said Shuji Zushi, a foreign ministry official.
"In these cases, there is a very strong conflict between the two sides and that leads to media attention or political action," he said.
Stephane Lambert spent years fighting to see his son after his wife and child moved away from their home in Japan - a case not covered by the Hague convention.
"The Japanese police don't do anything in this kind of case," he said.
"On the basis of a court ruling, I saw my son for a total of 14 hours for the whole of the following year, and not at all after that, because my wife refused the visits," he said.
"I can't think about my son anymore. Looking at a photo of him tears me apart. I've learned to forget him."
There are some signs of change: a panel of experts met in June to discuss new ways to enforce court orders, as well as the issue of joint custody and changes to the law.
But regardless of changes to the law, the pain of parental separation is always traumatic - as demonstrated by the case of Joichiro Yamada, who was 10 when his Japanese father and American mother split up.
"My dad told me: you live with me now," the 20-year-old told AFP, crying at the "horrible shock" of being separated from his mother.
"I spent a year with him. I wanted to go back to my mother. A year felt like an eternity."