Based on a novel, this is a dark psychological drama/thriller exploring complex themes of relationships, marriage and love. It also centers on themes of past traumas, psychological manipulations and complexities of different relationships. It's a powerful well-acted storyline that unwraps slowly but ever so steadily.
Thankfully, It's not a typical "Kdrama" series that you can find plenty of on Netflix and other streaming platforms lately but you wouldn't find Gong Yoo on one of those anyways.
The acting is quite solid especially from the main characters portraying their past emotional traumas and the slow healing they both go through finding each other again (as this was not their first encounter) and possibly lasting love from something that started as an unwanted, bizarre and disturbing contract marriage. But most marriages are contracts is one of themes the show explores and what binds two people together.
I haven't read the novel and I am sure this is not completely true to the book as others before it haven't been but on its own merit, this is a beautifully and well crafted production including the music scores and absolutely worth the watch.