From the Examiner:
The Japanese government is reportedly considering some significant changes to Imperial House Law. Specifically, they are looking at an ancient law which stipulates that if a woman in the royal family marries a commoner she is no longer an official member of the royal family.
Currently, there are only seven men out of a 23 member royal family, and five of those men are over the age of 60. The aging of the men, and the marrying of the women, present a major hurdle in keeping up with their public duties. The remaining men in the family just simply could not complete the number of engagements they currently do, without women to assist them. The anxiety around the issue has only increased with the recent hospitalization of the Emperor. Changes look likely to happen, and the most immediate effect will be to TIH Princesses Mako and Kako, both unmarried daughters of TIH Prince Akishino and Princess Kiko. Changes would also affect HIH Princess Aiko, 9 but obviously she is a ways from marrying age. Aiko remains the only child of TIH Crown Prince Naruhito and Crown Princess Masako and is not in line to inherit the throne due to the succession laws in Japan. There is currently not push to change the law since the birth of Prince Hisahito has slotted him as third in line behind his uncle and father.