This aspect of the series will end in one of these three ways
1. The ever popular no ending etc they will never name a girl why you ask? simply the Japanese get mad death threats have been sent to authors about these things. Fans GET PISSED if they pick one girl over the rest so to avoid this they leave it unsaid an "You pick" kind of deal. That's how the Japanese like it and anime and manga's main market is asia this care not for europe or the America's so your wants and wishes matter jack to them, because they make most of their money in asia so that the market they play to.
2. It would be Houki, only because if they do pick they will go with the cliche first child hood friend first girl introduced ending. This is one reasons I dislike manga's 99 percent of the times its the childhood friend or the first girl introduced.
3. It will be Chifuyu, now this gets flak but here is the thing, in Japan and asia this isn't a big deal. In may be to the US and others but again they aren't making this WITH YOU or such in mind. In Japan the incest ending is actually liked alot, plus really from the anime and LN Chifuyu has the most ground with him. Hell he ALWAYS notices her beyond the other girls its clear he considers them secondary to the rest.
On a side note, don't trust what Wiki's say in terms of relationships, alot of time wiki are edited by people who play favortism hell I read the Houki section on Ichika and hell could I spot that favortism.