Jeong-woo, who is newly married with Na-yeong, is secretly meeting Na-yeong's close sibling, Min-joo. Na-yeong, who is not aware of that fact, is worried that she is alone and tells him that he will introduce a good man to him, but she disappears when she tells him that she does not need a man and tells her not to do unnecessary things. Meanwhile, Na-yeong, who came home, tells this to her husband, Jeong-woo, but Jeong-woo also shows a grim reaction and does not care about it. Then one day, Min-joo visits Na-yeong's newlyweds in surprise, and the three of them fall asleep while drinking happily. While sleeping, Min-joo comes to Jeong-woo and does something amazing.
A fierce love between a close brother and the man of his sister is just beginning.