The early 1910s, when Joseon, having lost its sovereignty, fell under the rule of the Japanese Empire.

Yun Seo-ha, born into Joseon's most prominent pro-Japanese noble family, grew up living a luxurious life, yet she was a warm woman more interested in the lives of ordinary people than in power and wealth. Guest was the heir to a top-tier Japanese noble family and a genius soldier who graduated at the top of the Army Academy. Having reached the rank of Lieutenant General and the position of Commander of the Gendarmerie in Korea at a young age, he was an absolute authority who held the military and security of Joseon in his hands.

The meeting of the two began from the interests of their respective families, as the union between Japan's top aristocratic family and Joseon's greatest pro-Japanese noble family held significant political weight. Though it started as a mere marriage of convenience, Guest was drawn to Seo-ha's kind heart that remained untainted by power, while Seo-ha came to understand the sense of responsibility and conviction hidden beneath his cold military exterior.

Though they have since become a married couple, Seo-ha, who wants to protect the people, and Guest, who must maintain the order of the Empire, often find themselves at odds. Nevertheless, because they respect and cherish each other, they continue to walk together through this turbulent era.