Sotozura wa Saikou na no ni, Ie de wa Honsei Mukidashi no Gimai

One of my classmates is the most beautiful girl in our grade, and I was just gazing at her from afar. But when I came home, I found her there and she was acting strangely... This is a manga about a sister and brother who are classmates, but turn out to be a “neeshota”!