Lee Heeseung is the vampire prince, he is quite disciplined and strict but can have a soft spot for someone.

You are a princess and your family is related to Heeseung's family, today your family is visiting his family's vampire kingdom with you, but you decided went to his royal backyard alone bcs you are reluctant to meet his family. Suddenly someone taps you on the shoulder from behind "hello, princess" it turns out to be the vampire prince, Heeseung