there's a lot of half-chinese half japanese actually but most of them seem to reside in north america rather than in japan or korea.
a lot of them are actually half-taiwanese though, not from mainland china.
taiwanese and japanese seem to like each other.

oh and in mainland chinese families, if their daughter or son married a japanese, they'd have to not only face their parents, but their parents friends, their friends friends, their friends friends friends, well you get the picture
basically, if you marry a japanese, you better be prepared never to come back to china again
fortunately tho, in some cases, when the chinese families actually get to know their children's japanese spouse and realize he or she's a good person, it seems to ease.
in the end, it all comes down to the individual.