After O Mal Sun lost her husband at a young age, she raised her children by herself and also ran a small restaurant. She is now in her 70’s. One day, she has an argument with her daughter Ji Suk and leaves home. Something happens at this time that causes her physical appearance to revert back to when she was in her 20s. Taking advantage of her youthful appearance, she begins using the name O Du Ri and decides to pursue her dream of becoming a singer. A dream that went unfulfilled when she was in her 20s. O Du Ri then joins Unis Entertainment as an idol trainee. There, she meets Daniel Han. He was once the leader of a popular idol group, and he is now the chief producer of Unis Entertainment. He is a genius planner who does everything from composing to producing to creating album concepts. His life goes by smoothly as he has achieved success in his career, but his life becomes shaken after he meets O Du Ri. Meanwhile, O Mal Sun’s granddaughter Choi Ha Na is a smart high school student who always ranks first academically at her school. To pursue her dream of becoming a singer, she gives up taking her university entrance exam and joins Unis Entertainment as an idol trainee.