Both dramas feature protagonists, Jian and Gyeo Wool, with hidden lethal abilities and family secrets. Jian discovers the apparent suicide death of her uncle and is pursued by assassins, while Gyeo Wool is an undercover assassin. Both face threats from dangerous organizations and unexpectedly collaborate with other characters to survive increasing violence and danger. The plot centers on the combination of special skills, family betrayals, chases and unexpected alliances.
The protagonists are similar, and if you watch both dramas you will feel a dejavu between them.