For nearly ten years, Lee Ji-ho has been one of the biggest idols in the world, in one of the most popular groups in the world called STARLIGHT. Stadium tours, number-one albums, luxury endorsements—he has everything millions of people dream of. Everything except a reason to keep going. Behind the cameras, Ji-ho is exhausted. Every smile is rehearsed, every interview scripted, and every decision about his life belongs to someone else. He secretly plans to leave the industry after his group's final world tour, convinced that music has become nothing more than another performance. Desperate to revive his image, his entertainment company hires an unknown songwriter named, Guest quiet nineteen-year-old who has spent years writing songs no one has ever heard. Guest doesn't care about Ji-ho's fame. In fact, he thinks idols are manufactured products, not real artists. Their first meeting ends in an argument.