THIS Christmas Moises Garcia, a Nicaraguan living in America, got the gift he had spent almost four years and $350,000 fighting for: the return of his nine-year-old daughter. In 2008 Karina was whisked away to Japan by her Japanese mother. He set about fighting in the Japanese courts for the right to see her. During that period, he met her only three times. Their longest meeting lasted for only two hours.

Then he had a stroke of luck. Last April Karina's mother travelled to Hawaii to renew her green card. She was arrested at the airport and charged with violating Karina's custody agreement. As part of a plea bargain, the mother relinquished Karina, who became the first child seized by a Japanese parent to be returned to America via the courts. (Feel sorry for Karina, in the middle of this tug-of-love.)

Because of such cases, America is one of many countries that has pressed Japan to honour its promise to join the Hague Convention on the Civil Aspects of International Child Abduction. Japan proposes to do so this year. The convention sets rules for the prompt return to their normal country of residence of children under 16 who have been abducted by one of their parents. The State Department says Japan has about 100 such cases involving children of Americans. There are scores from other countries, too.

But for one category of parents—those living in Japan without access to their children—the Hague convention changes nothing. When parents separate, Japan's legal system does not recognise the joint custody of children common in other jurisdictions. Instead, children are put into the custody of a single parent after divorce. The family courts usually grant custody to the parent, most often the mother, who at that particular moment is in possession of the child—even if the parent has abducted him. The courts rarely enforce the stingy visitation rights of the “left-behind” parent. And so many fathers, in particular, vanish altogether from their children's lives. Every year as many as 150,000 divorced parents in Japan lose contact with their children, according to estimates gleaned from official data. Some do so of their own accord, but most have no say in the matter.

One such father, an ex-deputy mayor, describes the system as a conjugal version of the prisoner's dilemma. He says that when a marriage starts to break down, the unspoken question is: who will seize the child first, the mum or the dad? In his case, she did. For two years he has had no contact with his four-year-old daughter—even his presents are returned unopened—and all with the blessing of the family court. When he reminded the judge that the civil code had been changed to encourage visitation rights, the judge silenced him.

Satsuki Eda, who as justice minister last year pushed through the change in the civil code, says he hopes it will lead to more generous visitation rights. It may, he also hopes, one day lead to a serious consideration of joint custody. But, he cautions, judges are conservative, finding it “very difficult to change their minds”. And so, in a cruel twist, a country that has long sought redress for the past abduction of a few dozen citizens by the North Korean state tacitly supports vast numbers of abductions each year at home. “Many people in my situation commit suicide,” the estranged father says. “I can understand the feeling.”