Is it possible that areas of China fall to the japanese ruler because they inherit many territories in China thus starting a hundred years war in China either against a chinese emperor or a chinese faction?
I don't think that sort of foreign land inheritance was possible in the Eastern World at the time. Plus, until a few centuries ago Japan's demographic and political situation were such that it could only send out pirates to attack China.
A direct analogue to the Hundred Years War isn't going to happen, but maybe you could have something like Japan managing to grab several pieces of Chinese territory during one of the times when China is fractured into dozens of mini-states.