The story revolves around Yoo So-joon (Lee Je-hoon), a CEO of a real estate company, who has the ability to travel through time via a subway; and his wife, Song Ma-rin (Shin Min-a), who works as a photographer. So-joon foresees his future-self living miserably so he decides to marry Ma-rin in order to avoid that fate. As time passes, he learns to love her selflessly.[4]