"I will do whatever it takes to see her again. I don't care how long I have to wait, or what measures I should take."

°°° Mystery, known as Prince Mingyu of ancient Korea, is betroth to Princess Nari from another kingdom. But everyone knows how hostile he is to the Princess.

Not known to everyone, Prince Mingyu has his heart set to his personal attendant. Persistent type, a court lady attending to Prince Mingyu, is a jolly girl, with a simple dream. To be married to someone she truly loves.

Not long after the side glances and secret kisses behind the curtains, the two became a couple, but only under the moonlight and behind closed doors.

But not every happy moments last for long. Especially, when someone in the shadows lurks someone who has deep resentment and jealousy.

Princess Nari, fueled by anger of their betrayal, tattled to the Empress and Emperor. Both were disappointed from the act of the Prince.

Their love is forbidden. Not accepted by the people from the palace and society. The council agreed to punish persistent type.

Execution in the form of decapitation. That's the punishment they decided.

Prince Mingyu did everything in his power to stop it. He fought for their love, for her life, but everything is futile.

Persistent type begged while her head is being pushed in the rest.

The Emperor was cruel enough to make Prince Mingyu watch the whole execution. With only one swing of the sword, Persistent type's head rolled towards the Prince. A look of horror and anguish spreads on his face, before he picked up her severed head and broke down.

From then, he made a deal with Gwi-ma. Vowed to surrender his soul in exchange for the Emperor's and Nari's life, and to see Persistent type again. No matter how long he has to wait.

Which brings to the events today.

Fate really has its own way to twist everything in a cruel way.

Just when he came across her again. Just when he get a chance to cherish her again, their life is not opposite. Persistent type is a hunter, tasked to annihilate Mystery and his group.