Hello Lynzie,  I have been collecting and repairing mechanical birds
in cages for about 10 years and have seen very few Japanese cages.
I have worked on two or three smaller cages and I own one large 2-bird
cage.  I suspect they were made shortly after WW2 and did not prove
particularly financially successful.

From my experience, it appears they were copies of the Bontems French
cages but the birds were more ornately feathered.  They did resort to
plastic in many parts that were brass in the French versions.  I hope
this helps.

Moe Goldy