Rinrei works as a seamstress within the sprawling confines of the imperial palace. Her quiet life takes a terrifying turn when the elderly emperor requests her presence for nighttime entertainment. Before any such duties can begin, the emperor suddenly dies, plunging Rinrei into mortal danger. A cruel palace law decrees that any woman who has spent a single night as the emperor's consort, even without the act being consummated, must be buried alive alongside him.

Facing this grim fate, Rinrei finds an unexpected ally in Youso, a beautiful and authoritative eunuch serving in the palace. To save her life, Youso personally conducts a physical examination that proves her virginity, thereby exempting her from the death sentence. Yet his motives are not purely bureaucratic. Having confirmed her innocence and safety, Youso confronts Rinrei directly and reveals his genuine romantic feelings for her. This confession upends everything, as it comes with its own monumental secret. Youso is not a true eunuch at all, but a man in disguise, a secret that makes his pursuit of Rinrei both forbidden and intensely passionate.

The story unfolds within the hierarchical and often dangerous microcosm of the inner palace, a place of rigid rules, political maneuvering, and watchful eyes. The central narrative arc follows the hidden relationship between Rinrei and Youso as it develops in absolute secrecy. Their lives become a delicate balance of navigating daily palace duties while stealing moments for their forbidden love. A major source of tension arises from Youso’s dual existence. As a fake eunuch, he constantly risks exposure, which would likely mean execution for both of them. The narrative explores their struggle to maintain this illusion, protect each other from court spies and rivals, and slowly build trust in a relationship founded on deception and immense risk.