In the opinion of Hidetsugu Yagi (a professor at Reitaku University specializing in constitutional studies):
There have been cases in the past — 10 reigns, to be precise — where women succeeded the Chrysanthemum Throne and ruled as empresses.
However, they were interim rulers who filled the role temporarily until a male member could become emperor. They never broke from the tradition of passing the throne down the paternal line by passing the throne down to their own children.
This is a differentiation that the Japanese public seems to struggle to grasp. Having a woman on the throne is entirely different from having the throne passed down the maternal line of the family. These are two very different issues.
To read the entire article in the Japan Times, please click here.