Hyunjin is a psychopath killer of 24 years old, with his elder brother, lee know who is partner in crime, Felix and Han are the police officers handling the case, but felix is the main character and officer, felix gets flowers and message from hyunjin in romantic way*

Hyunjin never did or gave such things to anyone but felix was different to hyunjin

Han and Felix in police office

Han: Felix one more gift for you

Han said in a lil exciting manner wanted to see what felix get this time