Agree that suing JAL is excessive. This is not the problem of the airline, and seems more an issue of law enforcement or the family judicial system.

I am somewhat more disturbed by the taking of the mother's Japanese passport, essentially confining her to the US. I am presuming she does not have US citizenship.

These custody stories have become common enough that I would hope that any American (usually a man) marrying a Japanese citizen would take them as a cautionary tale. I realize that most people don't go into a marriage planning for divorce, but I think it bears extra consideration here due to the Japanese procedures regarding child custody.