Mid 30's Nam Hyun-Soo (Cha Tae-Hyun) is a popular radio DJ and entertainer. When he was younger, he was even more popular as a teen idol. One day, his apartment doorbell rings and a young lady named Hwang Jung-Nam (Park Bo-Young) appears and a young boy appear on his doorstep. The young lady tells Hyun-Soo that he is her father and he is also a grandfather to her son Ki-Dong (Wang Seok-Hyeon). Hyun-Soo not believing any of this, attempts to close the door, but when Jung-Nam threatens to go to the press he allows them to stay in his apartment. Complications arise when they are spotted outside and people assume they are romantically involved!