I finally watched the movie and there are some things before getting into topics, because of the way I watched them (I watched Old Boy first, secondly Sympathy for Mrs. Vengeance and finally this that was the first of the Trilogy).
Sympathy for Mr. Vengeance is a 2002 South Korean film directed by Park Chan-wook. It is the first part of his "vengeance trilogy" and is succeeded by Oldboy (2003) and Sympathy for Lady Vengeance (2005).
I watched it with my lady and my brother´s family and I have to say the script is absolutely amazing and the visual narrative is so powerful that the time passes so fast, the only tiny thing that I saw over the movie is that it is the naivest of the trilogy, probably I am taking in reference the last two movies, this is the most powerful movie in terms of writing and storytelling I have seen over the year.
Watch them all but please do the right thing watch them in sequence, do not do it as I did!
The original Korean title means "Vengeance is Mine", or "Revenge is Mine", but the alternate English title was ostensibly chosen to avoid confusion with the Japanese film of the same name.
The film was declared the best movie of 2002 by Harry Knowles.
Have a great day!!