Ilya is a military prostitute who is known for not sleeping with her customers because she can quell magical powers by singing. Even though her heart was broken by the loss of her hometown, she was determined to act cheerfully and survive strong. One day, Ilya was asked to do something in secret, and her partner was Sian Asberg, a ruthless magician known as the ``Silver Ice Knight.'' The higher the attack power, the more the magical power goes out of control, and in order to calm it down, soldiers usually sleep with prostitutes, but Cyan was known for not sleeping with prostitutes. Why such a cyan? She wondered, but when she was taken there she saw him breathing heavily. After that day's encounter, Cyan starts going to brothels just to listen to Ilya's songs. Sian is captivated by Ilja's performance, and Ilja is captivated by her. It seemed as if the two were falling in love with each other, transcending their social status as a nobleman and a prostitute, but... A pure love story between a lonely prostitute who cannot be honest and a knight who hides his purity under a cold mask.