Mr. Back () is a South Korean television series based on the web novel Old Man (), which was serialized on KakaoPage from April to October 2014. It stars Shin Ha-kyun, Jang Na-ra and Lee Joon. The series aired on MBC from November 5 to December 25, 2014, for 16 episodes.
Choi Go-bong (meaning "highest peak" or "highest salary") is a 70-year-old man who runs a large hotel conglomerate, and he's known nothing but greed and selfishness all his life. When his body suddenly transforms back into his 30s, he becomes gleeful at the chance to relive his youth. He renames himself Choi Shin-hyung (meaning "newest model"), and meets Eun Ha-soo, a part-timer who's just landed her first regular job. Because of Ha-soo, he learns what love is for the first time in his life. At the same time, he develops a relationship with his estranged son and troublesome heir, Choi Dae-han.