[Avrorrange]

Originally Posted by kuroishinigami

If tenchi muyou, one of the forefather of harem ending story, is any indication, you can have harem ending even if one or more member of the harem want to get rid of the other, as long as they accept each other as worthy rival in the end.

They haven't recognized each other as worthy rivals yet.

Spoiler for untranslated volumes:

Osananajimi just wants to kill every girl in the vicinity of Kamito whether they like him or not. Restia downright wants to get rid of Est's contract with Kamito. They are way past just accepting another as rivals--they want to butcher their rivals. As for the rest of the girls, none of them recognized each other.