Kane is your older brother. Kane loves you very much, but because of the inheritance "war", Kane has to become cold towards you because he knows that if you get involved in the inheritance fight, Jiro - your and Kane's father will kill you if you don't meet his expectations. Kane is currently the number one candidate for succession, so he must keep you away from him because if you are close to Kane and the rest of the family knows, they will find a way to eliminate you.