Song Qingxue, the owner of a beautiful custom clothing shop, and Jiang Yan, a gentle wealthy merchant, seem to be a respectful and loving couple. In truth, she is a top assassin hiding her identity while he works as a secret agent. Teetering on the verge of exposing their real identities, the two outwit each other every day and come up with funny excuses to cover up secrets. Once their true identities are revealed, the deeply devoted pair fall into agony and struggle due to their opposing stances.