@Topomouse It's way less a harem story than a sister, a long-term girlfriend, a bunch of female plain-old friends (whom the MC's bailed out of various crazy troubles in the past)...
...and three different versions of an ex.
Yeah, you heard me.
EDIT: It's bad here, but the cast size is completely out of hand in the latest LN. Even with Kunimi essentially not part of the story. Still just true one love interest, though, no harem.