"Please marry me."

A 2 billion won contract offered to a private military company's mercenary. The condition is one year of marriage.

"Customer, are you perhaps crazy?"

"You're the only lunatic that's fine with having a divorce history."

Lee Raehwa, the only daughter of Daesan Construction. In order to break free from her father's control and complete her painting, Raehwa hires a legal guardian for one year. But the only hope she hired, Gwon Itae, was unpredictable and crazy person The marriage and cohabitation, started as a contractual relationship, take an increasingly strange turn...

It tells the story of a woman who hired a mercenary to marry her for a year. She is the only daughter of a large construction company, who wants to free herself from her grandfather's control and dedicate herself to painting. He is a former soldier with an unpredictable personality, who works for a private military company. They begin a fake marriage for 20 billion won, but soon find themselves involved in several hilarious and dangerous situations. Will the two be able to keep the contract until the end, or will they truly fall in love?