Yuuta and Yumeha look like brother and sister but Kuzuha looks different, hair style and color. Makes me wonder if they might pull the non or half only blood relation thing bringing her into the harem. Or maybe it's just wishful thinking on my part since I have a thing for Kuzuha.
I don't get it, what harem. Chuuni had a pretty cut-and-dry thing between Yuuta and Rikka, cutting off the Nibutani route relatively early and not really introducing any other love interests through the rest of the story.