Ra On will do anything for money. Disguised as a man, she earns money by consulting and giving pieces of advice on love and dating. One day, one of her customers comes up to her with a pale face. It turns out that a lady who Ra On has been ghostwriting for the customer wants to meet a sender of love letters. She feels reluctant at first, but she'd do anything for money, so she decides to pretend to be her customer. However, instead of a pretty lady, Yeong, the handsome-looking man, comes to meet her. Yeong is the last hope of falling Joseon and the crown prince. The unpredictable romance between Ra On and Yeong unfolds at the royal palace.