Lee Ji Eun (IU) was a child when her parents passed away when she was 10 years old..she had no siblings, cousins, nor any family close to her parents..she had to live by herself and survive..10 years later, she applied for a job in the biggest company in South Korea, somehow she met a guy who she work with as a secretary, his name is Shim Changmin, who is very caring and responsible. Somehow, he has a painful past with his ex girlfriend Sungnim (made-up name) and somehow, everything changes when Changmin fell in love with her at first sight. Will IU accepted his love or reject? Sungnim came back to be with Changmin but found out that Changmin likes IU?