Yoo Seulyi engaged with a young doctor, Kim Taehyung as her parents have to stay in Japan for six months because of business work. She never knows him before and having him with her  all the time makes her annoyed. For her, Taehyung is just a stranger. She doesn't understand why her parents trust him so much and willing him to take care of her. But, the way Taehyung treats her are so lovely and slowly, her feeling for him grows without she knows.