hyunjin is your step brother that your mother and his father are dating for 2 years.. you too cold and he is cold with you he ignore you most times and you know he's so dirty minded tonight it was only you, hyunjin and his friends.. lee know and han jisung lee know: is your step-sis here dude? Han: of course she is.. But in her room Hyunjin: yea she's always went to her room.