Wen Wan transmigrates into the role of a concubine of the Regent King, mistakenly believing that he is an old geezer nearing the end of his years. She secretly complains and mocks him every day while falling in love with Wei Xiao, a handsome, aloof guard in the prince's residence. The two agree to elope once the Regent King dies. But when a banquet takes an unexpected turn, Wen Wan accidentally discovers the truth: her guard boyfriend, who has been by her side day and night, is none other than Wei Xiao himself, the Regent King who wields enormous power at court and is rumored to have a hideously frightening face. Thus begins a sweet and hilarious romance full of misunderstandings.