Not to spoil anything. I would have put this in S1 forum but it would give away spoils ...
Anyways,
It's weird, Iwao killed Lan Di's Father ( SunMing Zhao - i think ) and then to get revenge Lan Di kills Iwao. So in theory the 2 sons are left?
Ryo and Lan Di
Their both fathers gone Iwao kills Mr. LanDi then Landi ( son ) kills Iwao the sons live on....
Weird how shenmue is.