Kyous path was full of typical high school drama.
Pardon me for a second but I will sum it up:
"Oh Hai tomoya, I like you alot but my sister has a small crush on you so I am going to set you up but be obvious about my feelings for you. then I am going to make you second guess yourself while telling you not to waver from what I did for YOU despite how you really feel! Then just because I am such an awesome woman I am going to cut my hair and then tell you so that you think I am really my sister telling you. I know you are smarter than that but you REALLY have to play along for this one otherwise you and my sister will break it off and we will be together and we all know that will never happen hahahahahahahahahahahahahahahahahahahahahahahahahaha-don't touch my hair....."
Literally...
Thats her story in a nutshell.