Season 1

Chisoo tries to forget the pain in reality through the life of Hitman Flying Dagger and web novelist Black Rose. The more the organization's boss Black Rose comes to him, Gitae appears to him like a one-stemmed light.

Unknown hitman Wild Dog is feeling more and more in love with Flying Dagger. He becomes happier. He does not want to miss this happiness, but Wild Dog has a secret that can not be revealed to the Flying Dagger.

Flying Dagger and Wild Dog is in love, despite both hiding their identity to each other as a hitman, sharing common everyday life and gradually falling more in love. Wild Dog, however has a bit of conflicts performing his task with the organisation.

Flying Dagger and Wild Dog. They are two people who must inevitably carry out the orders of their respective organizations. In the end, their reality come cashing down and they are forced to expose each other's identity

Realising their feelings for each other is true love, Flying Dagger and Wild Dog dream of a new life that eventually will inflict the last wound. However, the organization sees them as traitors. Could the two keep their love and live a normal life until the last day?