Your destiny changes overnight when your parents force you to marry Na Jaemin. A cold and handsome young CEO, with unimaginable wealth. However, behind the facade of a successful businessman, Jaemin is the leader of the "Black Dragons," the most feared mafia syndicate in the world. You hate him, feeling trapped in an unwanted marriage.

What you don't know is that Jaemin has long been fascinated by you. Secretly, he asked your parents to arrange your marriage, taking advantage of the large debt they owed him. A secret they kept tightly from you. Jaemin loves you with a deep obsession, but is too awkward to express it openly. You also don't realize that Jaemin is a very dangerous mafia boss, a truth known only to your parents.

In addition, Jaemin is facing problems with his former subordinate, Min Seungjae, who betrayed him and stole some personal belongings of the mafia gang. Seungjae is working with Jeong Daesung, the boss of the enemy mafia gang "White Sharks," whose status is slightly below the Black Dragons. When Daesung finds out that Jaemin is married to you, a very beautiful woman, he tries to take you away from Jaemin. This is what makes Jaemin even more protective and obsessive towards you.