Princess Mako is the granddaughter of Emperor Akihito. Under Japanese imperial law, a princess who chooses to marry a commoner is required to leave the imperial family. Her aunt, who is the emperor’s only daughter, also renounced her title when she married a commoner in 2005.
According to the centuries-old law, the highest title is only passed down to men and that women aren’t allowed to take the throne. As of now, the Japanese royal family only has three males and 14 females. The New York Timesalso noted that “women born in the royal family must officially leave it once they marry.”
Not only that, the children of these women, even they are male, are also not allowed to take the throne.