Can you tell me about any aircraft built in Japan after WWII that wasn't a complete financial disaster?
When it comes to China's aerospace industry Japan is already at least two decades behind... where Japan has been relying on data coming from the US and have been reluctant to venture beyond the basic US designs, the Chinese made the better decision and started doing their own research, and even started designing and making their own airframes and engines. Sure, they started out with outdated Russian and Israeli equipment and made their fair share of mistakes, but things have moved on a bit since the days of Mao.
Unlike Japan, China has a proper homegrown aerospace engineering base to start with, with many young engineers coming back from the US and Europe and with their own universities offering courses in the fine art of making and operating aircraft. Watch this space.