Let will of the people decide succession issue | The Japan Times
[...] The number one reason that discussions on the matter do not move forward is that questions related to the Constitution and historical matters have not been separated. The Constitution says in Article 9 that the emperor “shall be the symbol of the state and of the unity of the people, deriving his position from the will of the people with whom resides sovereign power.” In short, the emperor’s position is determined by the will of the people, irrespective of the historical background of the imperial system.
[...] Based on the will of the people, the government effectively revised the Imperial House Law — by enacting special one-off legislation — to pave the way for Emperor Akihito to retire. In this way, the latest imperial succession was carried out without a hitch in accordance with the provisions of the Constitution.
The same logic applies to the question of imperial succession rules. Recent opinion surveys indicate that people are generally supportive of the creation of female-led imperial houses as well as allowing a reigning empress and succession on the maternal lineage.
[...]
These issues surrounding the imperial family under the Constitution on one hand, and the historical issue of exploring the roles played by the emperor system in Japanese history on the other, are subjects of entirely different dimensions.
If we follow the majority views of scholars, the origin of emperors (who can be traced with certainty) dates back to Emperor Keitai, who is believed to have ascended the throne in 507. It was when Empress Jito took the throne in 686 that the country started using the title “tenno” (emperor). She is considered to have become the model of Amaterasu Omikami, the mythical deity believed to be the direct ancestor to Japan’s emperors.
What this means is that the imperial family traces its origin to Amaterasu, a woman. [...]
Indeed, Japan has had eight reigning empresses (two of whom ascended the throne twice) — up until the late 18th century, during the Edo Period. Some of the emperors in our history are believed to have come from the maternal lineage of the imperial family — although the views of scholars are divided on the matter. The question of whether they had indeed been on the paternal or maternal lineage should be subject to purely academic study by scholars. That is an issue independent from the imperial system as defined under the postwar Constitution. We must not forget that.
Of course, each individual is free to take the historical background into account. Irrespective of whether the emperors in Japan’s history were 100 percent on the paternal lines of the family — or whether there were indeed emperors on the maternal lineage — it is only the will of the people that can determine the position of the emperor. This is the core of issue over imperial succession rules.