Police undercover agent Chloe disguises herself as a fragile young woman and signs a fake girlfriend contract with mafia boss Damon, waiting for a chance to steal the core transaction ledger. Facing wave after wave of assassinations from rival gangs, she repeatedly unleashes her elite combat skills to save him in secret, covering her tracks through self-injury and feigned amnesia. As layers of truth unfold, Damon turns out to be a police informant who has been undercover for five years. After the mission ends, Chloe returns to his office in full police uniform and signs a new contract for a lifetime together.