Sowon Han is awoken one night by a kiss-- but waiting for her is no fairytale prince! Her visitor is a mysterious demon who quickly vanishes after Sowon wakes. Was it all just a dream? When Sowon goes to school the next day, she is shocked to meet her newest classmate: Hyeon Yu, the demon who kissed her and declared himself her guardian! Hyeon is determined to rekindle their millennium-old forbidden love, but Sowon has no idea what he’s talking about. Will she ever remember Hyeon and their romance? Or is Hyeon destined to remain true to his demon roots and walk a darker path?