What are some other Korean movies similar to Forgotten(2017)?

I was amazed after watching this movie, because this movie didn't popped up on any 'popular Korean thriller lists'. I guess it's a hidden gem. So please suggest some more movies like this. And please don't suggest the obvious ones (Chaser, Oldboy, I saw the devil, Memories of Murder etc., they are on every lists). I mean something which is new, and very similar to Forgotten. Thanks.