TOKYO — Japan’s Princess Mako will postpone her wedding to commoner Kei Komuro to 2020 until after her grandfather, Emperor Akihito, abdicates next year, public broadcaster NHK said on Tuesday.

The couple, who had been planning to marry this year, want more time to arrange their ceremony and prepare for married life, NHK said, citing the Imperial Household.

Mako, one of only four royal grandchildren, must become a commoner after the union, according to laws governing the royal family. She and her fiance attended the International Christian University in Tokyo.