More than 400 since 1994 when the U.S. Department of State's Office of Children's Issue's (OCI) was established. Japan is internationally known as a black hole for child abduction.
Where does this 400+ figure come from?
It comes from data provided by the U.S. Department of State. Representative Chris Smith reported at the May 24, 2011 hearing in the House Foreign Affairs subcommittee, “Japan has by far the worst record of all. It has not issued and enforced the return order for a single one of the more than 321 American children abducted there since 1994, when the recordkeeping began.”