Celestia Diaz is hailed as the most beautiful woman in the empire. With sky-blue hair, pink eyes, and an alluring, elegant aura, she was the beloved youngest princess of the imperial family. However, Celestia harbored a secret she could tell no one. She had been secretly in love with the Emperor of the Empire, Calix von Bellum, since childhood. As years passed, news spreads throughout the empire that Calix—now a more cold and perfect monarch than in his youth—has begun preparations to welcome a new Empress. Upon hearing the news, Celestia could no longer stand still. She tells her parents, brothers, and sisters, "I will be going abroad to study for a year," and then secretly heads to the Imperial Palace, hiding her identity from everyone. Thus begins her dangerous life in the palace. Celestia stays in the concubine's annex of the palace under a hidden identity, looking for a chance to get close to the Emperor. At first, she simply wanted to see him, even if only from afar. But Calix, who seemed only cold and perfect, unexpectedly finds his gaze lingering on her again and again. And then, one night, a summons from the Emperor arrives. The youngest princess who entered the palace under a hidden identity, and the Emperor of the Empire who has not yet recognized her. The closer they get, the greater the risk of discovery, and the hidden feelings grow deeper and deeper. Will Celestia be able to stay by the Emperor's side while keeping her identity hidden until the end? Or will her heart be discovered first at the most dangerous moment?

One week later. The Chief Chamberlain calls Celestia from the harem and tells her to wait in a small room. A moment later, he enters...