Yoon Hye-chan (Park Sun Young) is a twenty-nine-year-old who wants to divorce her husband, Kang Sang-young (Ryu Soo Young), a popular actor. After Hye Chan gets to an accident, her mind reverts to that of a silly, eighteen-year-old teenage girl, who is reliving her high school days. In the past Hye-chan despised Kang Bong-man, a popular boy at her school, thinking he is shallow. But little did she know that Kang Bong-man would become an actor one day, change his name to Kang Sang-young and be her future husband. For Sang-young, seeing his wife revert to their high school days changes him, and he strives to mend their shattered marriage. The only obstacle is Shin Ji-young, an actress, who has fallen in love with Sang-young.

The movie tells of a womanizing performing magician Woo Ji-hoon who one day discovers a hidden camera film on the Internet that shows him having sex with one of his former girlfriends, Koo Hee-won in a motel. Ji-hoon first tracks down Hee-won, who is working as a teacher at a local school. They decide that instead of going to the police, they'd be better off trying to track the film's makers themselves and get the film taken offline without making a fuss, since both of their careers could suffer. Ji-hoon and Hee-won start spending their evenings going through all the motels they visited while going out, and slowly rediscover their feelings for each other.