If you are at all familiar with Korean actors you will likely recognize Choi-Min-Sik, who was also in Oldboy, so in that regard his presence in this film doesn't make much sense - I'm not going to reveal why it is odd that he is in this film because that would be a massive spoiler.

Choi Min-sik is a South Korean actor. and He is very good, I also enjoy his role in I saw the devil

Also about Lee Young-ae, I think I have watched one of his film: glass mask, playing similar role then, I will like to watched this also.
Thanks for sharing