My brother fell in love me

My name is Blair McCoug. I'm 15 right now and am freshmen right now. I live with my parents(Adopted) and my 16 years old brother Kai McCoug. My best friends Rosa Steinflied has a crush on him and Tiana Richards technically like my brother because he is the hottest,popular and funny guy in the school. And here I'm just a simple unpopular girl, also known as brother's sister informer because in my school right now all the girls are behind him,trying to at least trying to make boyfriend but Kai fell in love with me, why? He is my brother...and he has a girlfriend Laura, and I'm dating Josh...