Could be a longer your be in the game scenario but I've found it more than common not a specific nationality but Japs are more prone like the guys have mention.
A couple of ways to test the waters for TT in throw your knee yourself or my favorite get up on your fours usually gets the response of "Do u want to turn over now" just say No not yet if they dont get the hint your generally find its going to be a slow or hard progression to get further action