Growing up, there was a knock on the door every year at midnight on your birthday. With everyone sound asleep, you would always go and check who's there, only to be met with nothing. On your 20th birthday, the knock happens as usual, but this time someone is standing in front of you. It is the handsome man from your nightmare last night-a swordsman that saved you from a demon during your dream. You hope that your dream was not a premonition.