Furienna said:
You also keep saying, that they copied the Prussian succession laws, and that has got me thinking. Because during the WWII, there were no more kings in Prussia. The last Prussian king was also a German emperor, and he abdicated after the WWI. Was there even succession laws left in 1945, or did they copy really old succession laws, from before 1918? And I don't think any royal house in Europe actually prevented women from taking the thrown. After all, Christianity prevented all European royals from having more than one spouse at one time, which limited the number of legal heirs to the throwns, even though most princes and kings still had mistresses and illegitimate children. So even if they prefered men on the throwns, women could also become sovereigns, if they had no brothers. But in Japan, there were plenty of imperial boys born in very generation into the 20th century, since there were many concubines, and all their sons became legal heirs. So keeping all girls from the thrown made more sense in Japan than in Prussia.
The Meiji Restoration began in 1868, it came about as a response to the forced opening up of Japan by Commodore Matthew Perry. Up until then except for a small enclave near Nagasaki, no foreigners were allowed in Japan. Commodore Perry and his gunships overpowered the Japanese. It was decided by the Japanese leadership to go out into the western world and take what was best of what they saw and bring it back to Japan. Prussia was the superpower of its day, the Japanese admired its military strength and system of government centered around an Emperor.
Japan had Emperors up until then but were very much in the background, the rulers were the Shoguns, just before the Meiji restoration most Japanese of the time wouldn't have even been sure that the Emperor still existed.
The new Emperor was only a teenager, he was installed and the system of government modelled on the Prussian was introduced. The indigneous Japanese religion Shinto was reconfigured to centre around the Emperor and he became a direct descendent of the goddess Amaterasu. Also male only succession was introduced.
Regardless of whether or not Prussia existed Japan kept to the constitution it adopted in the 1880's, modelled on the Prussian.
The constitution adopted after WW2 changed the previous militaristic constitution, got rid of the minor royals and restricted the Imperial Family to the descendents of Emperor Taisho but still kept the female only succession. ( Which considering at the time, Denmark, Sweden and Norway also had female only succession wasn't all that unusual)
There actually were not many Imperial boys from the main line coming into the 20th century. Emperor Meiji had numerous children but only one surviving boy born to a concubine ( Lady in waiting is the polite Japanese term). Emperor Taisho ( Meiji's son) fathered 4 sons by his wife. In the 1930's Hirohito was pushed by IHA courtiers to take a concubine after his wife gave birth to 4 daughters in a row but he refused and eventually fathered 2 sons. Concubines haven't actually been used since the mid 19th century.
There are examples of European Royal Houses that wouldn't allow women to succeed well into the 20th century. Denmark allowed female succession in 1953, Sweden 1980 and Norway in 1991. The current kings of Sweden and Norway's sisters are not and never have been in the line of succession as they were born before the laws were changed.