>The difference is the conviction rate in China is over 10 times higher
Actually, it's not over 10 times higher; I double checked, Japan's is also 99.9% and has been for some time.
From: https://en.wikipedia.org/wiki/Criminal_justice_system_of_Jap...
Statistics from Wikipedia link: http://hakusyo1.moj.go.jp/en/61/image/image/h002003001001h.j...
If you just take guilty/not guilty, the % is actually 99.98% in Japan (e.g. 2011, 77 Not Guilty, 432,050 Guilty)