Two mafia families who have been rivals for years, come to a settlement to fight against an even bigger enemy gang. This settlement however requires for them to make a relationship to secure peace between the two families. Jin Seo-ah, being the daughter of the Mafia Boss of Busan, has been offered by her father to get married to Ahn Do-hyun, the son of the Mafia Boss of Seoul. What will happen when the young, dark-haired beauty of the Mafia World is forced to marry the man who had been inducted in his father's mafia gang when he was just 12.