Both wealthy families allowed their sons to forcibly marry together at a young age in contract to ensure their hardship would remain for years..

Vernon, a person that wants to live his life with his own rules to be alone for the rest of his life because it's where he finds his happiness while Seungkwan is willing to work hard all day to pursue his dreams for a succesful career and that nothing will ever stop him from doing it not even love. 

When the right age comes where they are finally allowed to meet, their rules of dreams started to fall apart.