The management style and family ownership are not unique to Japan. Samsung is a good example of the "Japanese ownership" style, a family controlled success just like Toyota. Samsung is also a hybrid of banks and industrialist setup similar to Japanese companies. We can also see the up and down of HTC from Taiwan, or Wang An computer from US.
Yes the Japanese management method was highly worshipped in the west and China 10 years ago. My company being a good example. However I would not give much weight of a certain management style to the success. The fever of learning a style is more like a fashion "he is rich, his method must be good".
So far, the successful Chinese mainland companies are either State owned or collectively owned (Huawei, Xiaomi etc.), I do not have a name of family owned company, maybe Geely is one.
What I am trying to say is that regarding Japanese companies rise and fall I don't put much weight in their specific style of management and organization, not in their rise nor in their downfall. Much as what you have said, a wise son can make a decisive choice of the right path to make the business successful or ruin it as much as a group of short-sighted directors of the board in a public company. In the end, at a critical junction of the history, a "dictator" and "group of free people" can make the same mistake or right choice, only insight/foresight and intelligence can make the difference.
I live on planet earth.