Japan's Princess Mako has married her college sweetheart, Kei Komuro - thus losing her royal status.

The marriage document for Mako and Kei Komuro was submitted by a Palace Official Tuesday morning and is now official, the Imperial Household Agency said. They will make statements at a Press Conference in the afternoon, but will not take questions because Mako showed fear and unease at the questions that would be posed, the agency said.

The Imperial House Law allows only male succession. Female members of the Royal Family must renounce their Royal status when they marry a commoner — a practice that has resulted in a decline in the size of the Royal Family and a shortage of successors to the throne.

Mako, who turned 30 three days before the wedding, is a niece of Emperor Naruhito. 

She and Komuro were classmates at Tokyo’s International Christian University.

They were engaged in 2017 and the two were set to wed the following year. But the marriage was delayed following news of Mr Komuro's mother's financial problems - she had reportedly taken a loan from her ex-fiancé and not paid him back.

The Palace denied the delay was linked to this, though Crown Prince Fumihito said it was important for the money issues to be dealt with before they got married.

Like Ms Markle, Mr Komuro has come under intense scrutiny since his relationship to Ms Mako was announced. He was most recently criticised for sporting ponytail when he recently returned to Japan.

Some felt his hairstyle was unbecoming of someone who was set to marry a princess.

The couple are expected to move to the US - where Mr Komuro works as a Lawyer - after marriage. The move has drawn inevitable comparisons to British Royals Meghan Markle and Prince Harry, earning them the nickname "Japan's Harry and Meghan".