Choi Ban Do (Son Ho Joon) and Ma Jin Joo (Jang Na Ra) are both 38-years-old and a married couple. Choi Ban Do has been burdened with being the breadwinner and Ma Jin Joo is a housewife with low self-esteem. Even though they loved each other when they married, they now hate each other. They both regret marrying at such a young age. The couple travels through time and finds themselves as 20-year-old university students when they met for the first time.