In the midst of the busy city Seoul, Yoo Seol, who is half mortal and half vampire lives peacefully alongside other mortals.

It all started when she was 15. Her curiosity about the life of mortals in the city leads her to be granted a special request; a chance to live within the mortal society outside of her coven. But with one condition; Seol has to come back to attend the dark academy when she turns 18 and leave the mortal world behind all at once. 

However, it all got tangled up when she fell in love with a mortal; Park Jimin.