When you start the game, go to the preferences and change the language to English. It's the only thing that isn't written in Hanja so you'll tell it apart right away. Also, the English is kind of... odd. It's not the worst I've seen, as you can still understand what is going on, but sentences are oddly structured and there are several typos throughout the entire thing.
If you're curious, the MC is the one with the black hat (2nd picture). IMO she's not particularly attractive, but the other characters seem to think otherwise. If you play this one, prepare yourself for a slow burner. I think I played 4+ hours yesterday and still no hint of a romance anywhere. It's a mystery VN first and foremost, with a few sparse choices here and there. Some of the choices are false and you're forced to pick something else, while others lead to bad endings. Thankfully, you'll know right away when you've made a bad turn.
I don't like games that give me fake choices and it feels like this is one of those examples. They should have just been honest and label this a kinetic novel, because that's what it really is (aside form choosing your RO). That aside, the story is decent. At least it's not one of those games where everyone's instantly fawning over the MC like they're on some kind of pheromones (though there's a plot reason for that).