Came well recommended - very much enjoyed, a different premise, but some interesting correlations with "The Parasite", also Korean and much applauded this year. Now - a bit of a meta analysis below - so don't click the read more unless you want major spoilers...

Now, at first glance - a peculiar film, the comedy of the father - his likability,  charm, bumbling inefficiency as one of the town cops. And, for all this charm - things develop and turn out quite horribly. (presuming you've seen it and I don't need to give away anything else.)

But why so, when most other films of the genre would take pains to give it a happy ending?

I think the meta here is the father - think ourselves here - at the beginning denies the possibility of evil, that these mysterious killings that are plaguing the village are possibly the work of malevolent forces, despite all evidence to the contrary. 

And, bumbling through the case, continuing to deny or challenge the possibility of evil, is compounded by his decency - his unwillingness to take action when confronted by it in the flesh.

So here we have an Everyman with an inability to realize, acknowledge or take action - efficient action, against evil, and thereby becoming it's victim. Had he taken efficient action when confronted with the evidence things would not have escalated so poorly.

Now to generalize - we have countless examples, from the Sacklers to Union Carbide through to Robert Pickton, Clifford Olson, Bruce MacArthur - all of which were active - and some of which still are - for the very same reasons.

Which should make us realize we need an efficient means of dealing with them, or we'll become as well their victims...