As a child, Hayato promised to marry his first love, Seraphy. Fifteen yeers later, he has become one of the world's greatest spies, all while never falling for the temptations of enemy agents. A mission to expose rival operatives turns chaotic when Hayato reunites with Seraphy, and each realizes the other is a spy. Now the pair must live together, torn between love and duty. The question is who will break first?