Koroshiya No Oshi summary:

A legendary assassin found the light of life. It was an underground idol!Endo Owal is the most powerful assassin in the Fujisan-kai, a huge black market organization. He was feared as a "killing machine" because of his ruthless work and overwhelming fighting power, but one day he decides to retire. The reason for his decision was to live his life proudly with Kaorin of the underground idol Ro~Xesia.Can a man covered in blood and sorrow protect the light of life that he has finally obtained?!