Actually neither in Mainland China nor in Japan the choice of the writing system has remained stuck to what had been used there for millennia.
In both Mainland China and in Japan the writing system has been reformed enough so that anyone who learns only the modern writing systems will have great difficulties to read any writing from before the first World War.
The reform was much more profound in Mainland China than in Japan, resulting in the Simplified Chinese writing system, so now Japan has remained with the more complex writing system.
In both Mainland China and in Japan the writing system has been reformed enough so that anyone who learns only the modern writing systems will have great difficulties to read any writing from before the first World War.
The reform was much more profound in Mainland China than in Japan, resulting in the Simplified Chinese writing system, so now Japan has remained with the more complex writing system.