"I swear to wield my sword for the infinite glory of the Esteria Empire and the noble spirit of chivalry." In the peaceful and robust Esteria Empire, Albert Anton is appointed as the bodyguard knight of the crown prince at the young age of 24. And then he meets the crown prince, Ellen Russell, a woman as beautiful as she is arrogant and cold-hearted. She presents a proposal shrouded in mystery: to become her fake lover and make her political rivals let their guard down. "Do not smile at anyone, do not show tears to anyone; only smile when I am by your side and show tears only in front of me. Sometimes, it’s okay to beg and plead." A political disguise romance between the arrogant crown prince who has the whole world at his feet and the bodyguard knight who wishes to protect only his beliefs.