This whole thing with Oreimo exposes the dark truth of Heterosexual relationships - that they need a secondary crux for even a dude to even touch a woman in the modern age.
The whole gig was a "fetish", but back then (and still in other places) - the woman was given to man on a platter, or drunk forced into relations. Ever since the concept of respecting women as human beings came to the front - not in the Chivalric way of keeping the "fetish" alive, but in to giving women a chance to find there own way in life, these issues have popped up in ways in both the east and the west that have created this addictions and concepts as away to cope with the reality of the situation.
So you have the whole edifice coming down. Women's movement in both west and east (with a bit of free market machinations) has shown that the whole gig of heterosexual courtship is a illusion, and what shows like KNJ, Oreimo and the like say is that none of our concepts of law, religion, etc can solve these issues because the very basis of this is the self hatred of man towards himself and by extension, everybody around him. Man is the king of nothing and needs the illusions (even if they were created by media, social structures of how men relate to one another and so on) in order to live.
This is the reason why I see shows like Oreimo as the symptom of a larger issue and not nessaerly the cause. Basically, man could never be with women or even have sex with one unless given one, the woman being submissive to the man, or if Zizek is correct - man becoming apart of a nightmare where his desire is realized. The only reason we even are with females in the first place is that its acceptable by social rule and not by need. Anybody can have kids, but that doesn't even mean the two that brought the child in the world even really wanted to be with each other.
So, to even have sex anymore - man needs the fetish. That's were all the dark shit comes from. That's the true lesson of Oreimo, KNJ etc.