This is the best surprise I had since "It's ok not to be ok", I think even better y many aspects... And, It doen`t make any sense there isn't a Romance tag in this one. There is more romance than in many dramas that were labelled that way (Train is one of those). This one has many amazing points:

ORIGINAL STORY
UNIQUE WORLD/LORE/AMBIENT
AMAZING EFFECTS
ACTING QUALITY OVER THE TOP EVEN WITH THE EXTRAS
RELATABLE CHARACTERS
OUTSTANDING FEMALE PROTAGONISM
HEALTHY RELATIONSHIPS
REAL LIFE VALUES
SUPERNATURAL WORLD WITHOUT CLICHÉS
INTEGRATING COLECTIVES NATURALLY
UNEXPECTED PLOT TWISTS
VISUALLY INCREDIBLY INTELLIGENT AND SPECTACULAR COLORS USE
CHARACTERIZATION AND COSTUMES UNUSUALLY NATURAL AND COMPLEX (PEOPLE WITHOUT ANY MAKE UP)

If you pay attention to the bad critiques and the lousy ranking you are going to miss a great piece of art, a trully hidden gem.
And, Nam joo hyuk playing a not sexualiced character for a chance and totally roking it like a boss.

JUST WATCH THE FIRST EMISODE IF IT DOESN`T EXITE YOU A BIT, THIS IS NOT FOR YOU.
MANGA/ANIME LOVERS DON'T SKIP THIS ONE!!