Young Eun lived with a family ever since she was an orphan and then fell in love with Do Hyun who is 5 years older than her. However, Do Hyun's family did not approve of Do Hyun dating Young Eun. As a result, Young Eun eventually left Do Hyun and marries a doctor, Joo Kyung Woo. Although Kyung Woo acts like a gentleman, he is actually a mama's boy with multiple and complicated personalities. Though he treats Young Eun well, he believes everything his mother tells him and will turn on Young Eun at any moment. Jin Ah is a pediatric medical resident and falls for Do Hyun. But she is unsure of his relationship with Young Eun. Do Hyun decides to marry Jin Ah and after the wedding, Young Eun has had enough of Kyung Woo's mother. She decides to leave Kyung Woo. What will happen between Do Hyun and Young Eun? Will they realize they can't leave without the other?