The first female assassin, Lu Anning, misunderstood that the chairman of a top conglomerate, Gu Lin, was a unscrupulous businessman and received a mission to assassinate him. The two became acquainted as a result. Gu Lin noticed something was wrong and sent someone to investigate. After learning that everything was a conspiracy of the opponent, he ordered the acquisition of the opponent's company and blocked all possibilities of his comeback. However, he did not expect the opponent, who was forced into a desperate situation, to start planning revenge against Gu Lin at all costs. On the other hand, after returning to China, Lu Anning regained her pitiful stepdaughter status and, under the arrangement of her stepmother, divorced her ex husband. It was only then that Gu Anning discovered that her ex husband was actually Gu Lin. He, like himself, possesses a vest and disguise. Later, Lu Anning was drugged and framed by her stepmother, and had an unexpected one night stand with her ex husband, becoming his bodyguard. In Lu Anning's eyes, Gu Lin is a person who is neither treacherous nor unscrupulous. Gu Lin clarified the rumors and promised Lu Anning that as long as Lu Anning became her bodyguard, she could fulfill one of her wishes. Female initiative, she wants to use Gu Lin to retaliate against her stepmother and sister. Gu Lin seized the opportunity to strike while the iron was hot and told Lu Anning that as long as he stayed by his side, he could more easily come into contact with the assassination target who was a member of the upper class, and the mission could be completed more conveniently