This is one of my all-time favorite Kdramas! It has everything you could want! Supernatural elements, romance, mystery, kick-butt female, action, and comedy. The plot is intentionally outrageous! It keeps you laughing the whole time.
I loved the connection between the main characters. More than just the main couple, the side couples are also great! And the friendships are beautiful.
This one really allows you to get to know the characters before the end of episode one! It keeps you on your toes, though, as it progresses.