The princess, who is due to marry former college classmate and 'commoner' Kei Komuro, will not walk up the aisle for another two years due to 'insufficient preparations'.
There has been speculation in Japan that the change of wedding date could be down to pressure the palace is feeling from rumoured criticism of the groom's family background.
The couple were engaged in September 2017 and due to tie the knot this November however the Imperial Household Agency blames “a series of important ceremonies next year” for the delay.
It was expected that the 25-year-old granddaughter of the emperor of Japan would step down from her role to marry her commoner boyfriend, giving up her royal title and becoming a regular citizen. This is only the case for female members of the family however, and male royals can marry 'out' and keep their status.
According to the Guardian, agency official Takaharu Kachi told reporters the decision was not related to tabloid reports about disputes in the groom's family over money Kei's mother borrowed to cover her son’s tuition and never repaid, Japanese media reported.
“We have come to realise the lack of time to make sufficient preparations for various events leading up to our marriage this autumn and our life afterward,” Mako wrote in a statement. “We believe that we have rushed various things too much.”
The couple were due to hold a ceremony to formalise their engagement next month, however that has since been called off and no new dates for the wedding were given.