What happens if the fabled King of Demons looks for his heart. What happens when a modern day girl is the holder of his heart. 

Over 1000 years old, Seductive looks that make the nicest of people bring out their darkest desires. He is the Demon King himself, still roaming the world searching for the one vital piece of himself he declares missing. He is the Demon King, Han Jiyong

At age 26, She has it all. Success Beauty and wealth all at her fingertips. An Heiress envied by all but somehow unhappy with the world and all its cruelty. The pure hearterd and innocently soulded beauty. She is the holder, Irene Bae

But what is the fate that ties the two together as their fates are tied by a single piece of each other. Can the power of the Demon King's Heart truly decided if the world prospers in piece or falls in to misery and anarchy 

CAST

Han Jiyong - "Good and evil don't matter to me, only you do"

Irene Bae - "Is this really all the good left in this world?"

--minor characters--

Suho - "Trust me, I will change the world if you want from me?"

Wendy - "Can a they really be trusted?"

Seulgi - "Happiness always exists, you just gotta look hard enough to find it"

others will come and go as the story progresses