This show needs no introduction nor does its leading lady.

A show that depicts the darker side of humans and how monstrous and inhumane they can get. A broken and scarred girl who swore revenge on those who made her life hell returns and unleashes the same hell on each and everyone of them making their lives worse than death.
She decides to take away everything they had from them and in the process meets a guy who is too broken and scarred just like her. He becomes her support when no one in the world did that for her, making her start to believe in others again.
The show will make you feel so many emotions. You will cry for the victims and hate the guts of the bullies. The cast has nailed their roles be it of the good or bad one.
Song Hye Kyo proved with this show that she ain't just a pretty face but a phenomenal actress too who can pull of both sweet and darker roles.

(The saddest part is that the things that are shown do happen in real life too and even way worse. Many have faced it growing up and many are facing it even now and this will continue on cuz such monsters exists everywhere at any age groups. I do pray for the well being of those who have suffered such atrocities and hope they are able to move past those scars.)