The bill necessary for Japan to join the treaty for handling cross-border child custody disputes has passed the Diet.
Japan is now assured of ratifying the pact by the end of the fiscal year next March after all the domestic procedures are completed.
The 1980 Hague Convention on the Civil Aspects of International Child Abduction sets out the rules and procedures for the prompt return of children under 16, taken or retained by one parent following the failure of an international marriage, to the country of their habitual residence if requested by the other parent.
The bill was submitted to the Diet in March 2012, but it scrapped when the Lower House was dissolved for the December general election. It was resubmitted and approved by the Lower House earlier this month and by the Upper House on Wednesday.
A central authority will be set up in the Foreign Ministry to take charge of locating children who have been taken away and encouraging parents to settle disputes through consultation.
If consultations fail, family courts in Tokyo and Osaka will issue rulings. The bill allows a parent to refuse to return a child if abuse or domestic violence is feared.
Japan is the only Group of Eight nation yet to join the convention.