In announcing the delay, the Agency also cited "a series of important ceremonies next year" – seemingly referring to the handover of the Chrysanthemum Throne. Princess Mako is Emperor Akihito's oldest grandchild. The 84-year-old will abdicate on 30 April 2019, with Crown Prince Naruhito taking the throne.
Mako and Kei – a law firm worker – announced their engagement in September. Their marriage will mean that the princess will lose her royal status; under Japanese law, female imperial family members forfeit their status upon marriage to a commoner, whereas male members do not. She said at the time: "I was aware since my childhood that I'll leave my royal status once I marry. While I worked to help the emperor and fulfil duties as a royal family member as much as I can, I've been cherishing my own life."
The couple met five years ago while studying at the same university, and Kei proposed after dinner one evening in December 2013. He said he was happy and thankful to have been accepted by her parents, Prince Akishino – second in line to the Chrysanthemum Throne – and Princess Kiko, and her grandparents, Emperor Akihito and Empress Michiko.