Former teen idol Nam Hyeon-soo (Cha Tae-hyun) is now in his thirties and works as a radio DJ. A young woman named Hwang Jeong-nam (Park Bo-young) sends stories about her life as a single mother to the radio station Hyeon-soo works at, telling him she is going to meet her father. He then finds out that he’s her father when she shows up at his apartment with her son Ki-dong (Wang Seok-hyeon). She tells him that her real name is Jae-in and that her mother was Hyeon-soo’s first love Jeong-nam. Hyeon-soo doesn’t believe it at first, so they undergo a DNA test and the results confirm that they’re related. Jae-in dreams of performing on stage as a singer, but Hyeon-soo fears that if she does, their paternity scandal might get out. Because of Jae-in’s rising popularity, Ki-dong’s father Park Sang-yoon (Im Ji-kyu) finds her. They meet and chat, with Sang-yoon initially under the mistaken assumption that Jae-in is romantically involved with Hyeon-soo. When Ki-dong later goes missing at Jae-in’s performance, Hyeon-soo realizes that he really does care for his daughter and grandson.