For Sam Lui, coming home to an empty New York City apartment is still wrenching even after more than a decade. His son Ezra was abducted in 1999. Lui said Ezra's mother has since changed his son's name. The father said the e-mails he receives from his now 13-year-old son are typically requests for money and expensive gifts.
"There's no closure to this issue. It's not like as if someone died where you find the closure. There's no closure," Lui said. "My kid's been gone for 11 years. Do I have hatred for my ex-wife? Of course I do."
For all of the fathers' efforts to find and communicate with their children, many of their ex-wives are living openly in Japan.
It took ABC News less than 24 hours to locate Ryoko Uchiyama, a woman who is on the FBI's Most Wanted list for parental kidnapping, after she fled in 2006 to Japan with baby daughter Melissa, from the California home she shared with American Patrick Braden.
Uchiyama's mother confirmed over the house intercom at their front gate that Ryoko Uchiyama lived there, but said Ryoko was not home. She also confirmed that Melissa, who is now 5 years old and goes by the name Hinako, lived there as well. As ABC News was speaking with Uchiyama's mother via an interpreter, a little girl's voice was briefly heard calling for her grandmother over the intercom.
Ryoko Uchiyama's sister, Seiko Azuma, who lives within walking distance, told ABC News that there was a story to tell, but that she had to follow the wishes of her parents and remain silent.
South of Tokyo, in a more rural town in the Chiba prefecture, ABC News found the family of Reiko Nakata Greenburg Collins, who is also listed on the FBI's Most Wanted list for the 2008 kidnapping of Keisuke Collins, now 7 years old. They declined to comment.
A neighbor confirmed that Nakata and Keisuke had moved from the family home in a suburb west of Tokyo, but returned for visits.
When local police were called to investigate ABC News' filming in the neighborhood, they were shown a copy of Nakata's wanted poster and Keisuke's abduction poster. When asked whether they would do anything about it, they said no -- that Nakata, despite an active federal U.S. arrest warrant, was not violating Japanese law.
Keisuke's father, Randy Collins, who has not seen or heard from his son since Nakata disappeared with him from their southern California home, called on President Obama to get involved.
"He took an oath to protect the citizens of this country. Why are our children not a priority to you?" he asked. "Please explain to me why my son doesn't mean anything to you."
For Braden, who also hasn't seen even a picture of his daughter since her abduction, the solution starts on U.S. soil.
"If we can break the back of this issue by enforcing the laws that are broken by Japanese citizens on U.S. soil and returning those citizens to face justice … it can be very simple," he said. "And that will open the floodgate to resolve every single case and it will help worldwide."
Though several of the fathers admitted to fleeting moments where they considered hopping on a plane to Japan and getting their children back, only one has tried it -- and failed.
Christopher Savoie, whose children were abducted by his ex-wife Noriko in 2009, was arrested by Japanese police as he tried to take Rebecca, now 8, and Isaac, 10, to an American consulate in southern Japan.