"We found that the Japanese occupation of this large part of China was not justified on the grounds of self-defence and that the new state which was set up was a Japanese protectorate rather than a case of Manchurian self-determination",-The Lytton Report
This report was commissioned by the League of Nations and it indicted the Japanese for their invasion of Manchuria and set forth the League's policy towards the Manchurian crisis.
Mr. Lytton was correct. The Manchukuo state was only a country in name only. The Japanese controlled the affairs of their puppet regime in the region and modelled it's government after the one in Tokyo by instituting a cult of Emperor worship around Pu Yi and allowing the Manchurian police to arrest anyone for 'thought crimes'. In regards to it's legal system, every issue of the
Manchukuo Legal Advisory Journal always contained a summary of the most recent rulings by the Supreme Court of Japan, and the reasons why the Japanese Supreme Court had ruled in these cases.
Manchukuo had an extensive system of courts at four levels staffed by a mixture of Chinese and Japanese judges. All of the courts had both two Japanese and two Chinese judges with the Chinese serving as the nominal superior judges and the Japanese the junior judges, but in practice the Japanese judges were the masters and the Chinese judges puppets.
Though, a interesting fact is that Manchukuo became the place where Japanese judges would go if they couldn't cut it in Japan. This was because the more competent Japanese judges did not want their decisions to be second guessed by the Kwuntung Army, who held the real power in Manchukuo. By contrast, the best of the ethnic Chinese law schools graduates in Manchukuo chose to work as part of Manchukuo's judicial system, suggesting many middle-class Chinese families were prepared to accept Manchukuo
.
In Manchukuo schools, Japanese was the primary language taught. Chinese was secondary.
Manchukuo did experience rapid economic growth during it's brief existence, but this growth was for the benefit of the Japanese military who made Manchukuo into a 'national defence state' in which the Manchurian people would be mobilized for war even during peacetime.
The Japanese influence over the Manchukuo state would have to be lessened in order for the people of the region to accept it as a legitimate country, though this would defeat the purpose of creating Manchukuo altogether, as Japan wanted Manchukuo to be a showcase of the 'civilization' it would bring to Asia.