I’m always fascinated when behaviors that would normally be called “fetishes” get a pass because they crop up in a non-sexualized context.

So much of what we think of as “kinky” is stuff that people do every day without ever thinking of it as sexual behavior — it’s only when it’s being done by a smiling, naked model that it becomes kinky.

The point was driven forcibly home for me the other day when I went to see the new Studio Ghibli film From Up on Poppy Hill. It’s an animated film, and not exactly one for kids, but it’s hardly adult entertainment either — the story revolves around a pair of high school students and their efforts to save an old clubhouse from being demolished by the school board.

(That synopsis does it a disservice, just so we’re clear. It’s a very good movie with a lot to think about, and I’d recommend it to snobby film-studies types and casual movie-goers alike. My point here is to assure readers that haven’t seen it that it’s not one of those perverted Japanese cartoons you watch religiously have heard so much about.)

Without going into too much detail, two of the characters — a boy and a girl — begin to develop what is obviously a romantic relationship, and then discover that they may in fact be brother and sister.

The characters are drawn similarly, to lend believability to the potential blood relation.

And for a movie that doesn’t even feature a kiss scene, they spend a fair amount of time trying to reconcile being related with their increasingly romantic feelings for one another.

Things come to what would, if they were wearing less or touching more, be a very steamy climax when the girl, Yumi, climbing onto a streetcar, tells the boy Shun that “even if we can’t do anything about it,” she loves him. He replies in kind, and they watch each other vanish into the distance.

This is, not to put too fine a point on it, pretty kinky stuff. They are openly declaring their passion for one another, while under the impression that they are blood-related brother and sister, and they verbally acknowledge the taboo against their relationship even as they defy it. It’s the stuff incest and pseudo-incest smut is made of.

And yet, because it’s a pair of underage characters who aren’t depicted as acting on the romantic impulse in any physical way (an unrealistic underestimation of teenage hormones, that, but we’ll let it slide), the kink flies with nary an eyelash batted.

Interesting to see at a time when sellers of written erotica are flip-flopping back and forth on exactly what sorts of incest and pseudo-incest they will and won’t allow — some of them in very specific terms; others in blanket bans.

It was, to my mind, a good reminder that “perverted” is all about how physical you get. You can put a brother and a sister falling in love with one another on the big screen, so long as they don’t kiss.