No one could have imagined that An Xiuzhi (Kim Ha Neul), who looks beautiful and lovely, is actually a senior intelligence officer with six years of work experience. Given the sensitivity of the profession, even Xiuzhi's boyfriend Li Zaijun (Kang Zhihuan) does not know his girlfriend's true identity, and therefore the two have many misunderstandings. Even when Jaejun is about to go to Russia to study, Suzhi is still busy catching criminals, and their relationship is frozen. Three years have passed in a flash. Jaejun, who returned from Russia, is now an international accountant, and his true identity is also an intelligence officer. He has just entered the industry and has made many mistakes. At this time, he was ordered to return to his country to investigate a Russian gangster. By coincidence, he met Xiuzhi disguised as a cleaner. The two did not know each other's identity, let alone that they were carrying out the same mission...