Here we have the legendary family back! The glory of the family is marriage?! The great plan of marriage is unfolding! The legendary Jang's family who holds money and power! There is only one troublemaker for Ms. Hong, the head of the family, who is Jin-kyung, the youngest daughter who declared to stay single. One day, 'Jin-kyung' has a one night stand with 'Dae-seo' whom she saw for the first time. When the Jang family find out about this, they start all sorts of plots to get 'Dae-seo' who has the best condition of being son-in-law to marry 'Jin-kyung'... The biggest task ever thrown to the Jang’s family! Will the marriage of the century be successful?
Hyun-su and Soo-jin have just gotten married. Seemingly out of nowhere, he starts talking in his sleep. 'Someone’s inside.' From that night forward, whenever he falls asleep, he transforms into someone else with no recollection of the night before. Soo-jin is overwhelmed with anxiety that he’d hurt her family while she sleeps and can barely sleep a wink because of this irrational fear. Despite sleep treatment, Hyun-su’s sleepwalking only intensifies, and she begins to feel that her unborn child may be in danger...