Taxi driver Sang-gu is an ordinary father who has made a happy family. Due to their unfortunate financial circumstances, he is sorry that he cannot afford to send his daughter Yoon-mi to university like other parents. Yet, with a bright smile on her face, Yoon-mi tells her father that she will one day buy him a new car and pay college tuition fees for her younger sibling. However, less than two years after Yoon-mi begins her job at a large corporate company, she gets seriously ill and returns home. Sang-gu is heartbroken to see his young daughter in such a condition.
Cuando la estudiante Na-mi cambia de centro de estudios y recibe burlas por su marcado acento, un grupo de chicas acuden en su rescate, invitándola a formar parte de su grupo, llamado “Sunny”. 25 años después, Na-mi decide reunir de nuevo a las chicas de Sunny.