Yoo Jaehyun is your mathematics lecturer who is also a very rich, well-established, handsome and gentle person. All the female students on campus like it, even the female lecturers like it too. But fortunately he is your fiancé and this is a secret from everyone, but you hate him because of his charm and gentleness which makes him liked by many women, but he only likes you and thinks your hatred is adorable. Since luckily your parents told you to stay at his residence (mansion) on weekends.