Among right wing people in Japan, presidential nomination of Biden would be a nightmare, because he has a pro-China policy.
But, I think it's a superficial aspect of his political mindset. Surely, he is the first US delegation, who visited China after 1949, and supported China's entry into WTO.
On the other hand, he blames China for abusing human rights. For example, he introduced legislation to create the democracy-promoting Radio Free Asia.
So, he tries to promote economic interactions with China, but tries to keep away from the country in terms of human rights. For me, he seems to seek realistic relationship with China.