The case concerned two children, born in 2008 and 2013 to married parents.
The mother held a Chinese mainland passport and was working in Japan. The father held a Hong Kong passport and operated a procurement business, on a part-time basis, between Hong Kong and Japan.
In April 2008, the father moved to Japan under a visa dependent on the mother, who was working there. Following the birth of the children, the father took on the role of carer alongside his part-time procurement operation.
The children had Hong Kong residency and passports through the father.
In June 2014, the relationship of the parents began deteriorating.
On 1 August 2014, the father went to Hong Kong with the children. He rented a flat and arranged for the older child to go to kindergarten.
On 4 September 2014, the father commenced divorce proceedings in Hong Kong.
On 7 November 2014, the mother commenced proceedings for the return of the children to Japan on the basis of the 1980 Hague Child Abduction Convention, and of the Child Abduction and Custody Ordinance which implements the Hague Convention in Hong Kong.