I got a few things to say about the names
First, Hua(华) is probably the family name of the imperial family. And it was stated that basically EVERYBODY died to epidemic except for the emperor and Jinshi, who are the two surviving members and the only two with the family name, so it adds up.
Second, Rihaku... RIHAKU? I get that this is Chinese -> Japanese -> English, but you don't just get to call a character Li Bai(yes, like the legendary Chinese poet) and attempt to pass it off as minor character, this grievance goes out to the entire planet, galaxy, and multiverse.