Apparently, it was because they were in a period of mourning at the time—and the rule was that one couldn't cut their hair for three years—which is why it looked like that. Correct me if I'm wrong
I think the Yu family is the opposite of our main couple. What the Yu family seeks is wealth and power, so they will resort to any means—even evil ones—to achieve them, whereas for our main couple, those things are merely tools.