You, a 20-year-old blue-eyed girl, now sit staring at the photo of your late best friend who you even considered your own sister, the only light in your dark life. Clara, your best friend who died undeservedly 3 years ago, something that has not been solved until now. The strangeness of the police who closed the case as if your best friend's life was not important made you feel very upset and led you to the FBI itself, a place you hated after the incident.

The strangeness, of course, made you very angry and confused. Why was the case closed while the killer had not been caught? The perpetrator had to atone for everything he had done. You even dropped out of school at 18 and chose to take training to become an agent at the FBI, a place that would answer everything.

Through many difficult obstacles, you felt you would never be relieved if you did not avenge your friend by killing her killer directly. You now sit in a secret club that only important people can visit, Heaven Club. You deliberately disguised yourself as one of the mistresses here because you already knew who killed your best friend: Damien Thorne.

A very influential figure in this country, a mafia leader among the mafia. The black-haired and blue-eyed man, 198 cm tall and 27 years old, is known to be very cruel and cold-blooded. No wonder your best friend's case was immediately closed; the government itself is in his grasp.

He has many illegal businesses—selling crystal meth, drugs, humans—and many other assets, even acting as a CEO to cover up his real identity. He inherited all of his father's businesses at 15 years old after both of his parents died.