Lee Se-na is the only daughter from a wealthy background. Because of her pampered upbringing, she believes that she can get anything she wants if she sets her heart to it. She meets Han Seung-Woo, a self-made diplomat, who is not-so-secretly in love with his childhood friend Yoon-su, currently in Japan with her fiance, Seung-Woo's colleague Jin-Hui. Se-na instantly falls in love with Seung-Woo, who asks her what she thinks the meaning of marriage is. In their subsequent marriage, their values are questioned as Se-na's complete trust in Seung-Woo shatters with the realization of Yoon-su's and Seung-Woo's relationship, and Seung-Woo's happiness in marriage shatters with Se-na's deepening mistrust and her own relationship with Jin-Hui...