Throughout the entire 40 episodes many different topics are hit including deep ones like obsessiveness abuse cheating & heartbreak. You will learn to hate some of the side characters in this story due to their actions and in the end I still dont understand why some of them did what they did to the others but it happens in plots like this. The acting in this was amazing especially Ryu Soo Youngs he did a great job portraying Ma Ris husband and his obsessiveness. Source: https://www.artikelschreiber.com/en/.