I just came across a fried egg thread on a Japanese website (and eggs is kinda timely topic in the US now. lol). By reading many comments, it appears that drizzling soy sauce is the majority in Japan, with so-su being the second. There are some people who put ketchup and even mayo (or mayo & so-su). Salt & pepper seems to be a minority.
I grew up eating fried eggs with soy sauce (I guess I was in a majority) but now I'm either salt & pepper or hot sauce.
How about you?