Gu Cheng, who was thrown into a mental hospital by his family, met doctor Ye Zhuo. Ye Zhuo knew the taboos between doctors and patients but fell in love with Gu Cheng at first sight. Gu Cheng could not understand what he wanted from him, so he killed the person who had ruined Ye Zhuo's life. The two people responsible for the murder were bound to be expelled from society. After death, Ye Zhuo opened his eyes and saw ice. In the cold underground darkroom, he was born as a tool. As he grew up, he searched for Gu Cheng for eighty years. Originally, he would never find him again in this life. When he was allowed to be used as a gun, he met the familiar person. Looking at Gu Cheng's cold and powerful appearance, he secretly decided that he would no longer be manipulated by others and be strong enough to be by Gu Cheng's side. Gu Cheng understands the ways of the world, but is very unfamiliar with relationships. With Ye Zhuo's company, he gradually feels human nature.
Purpose: Mutual redemption