>>281086582
> And hell, creating a scenario where all girls are on board with sharing is pretty hard to naturally.

If you make setting supernatural to some degree, exaggerated or comedic it isn't that hard. Like >>281113577 said any kind of family and tight group of heroines being together for some times is prime setup for achieving a true harem series. Of course if entire series is about girls viciously competing for MC cock it significantly reduced chances of becoming true harem, at best you get routes.