The main chracter is Yu Hyechan who is 29 years old.Hyechan is married to Kang Bongman who is her old classmate in high school whom she despised and hated because of his cocky attitude.But later she fell for him after being rejected by Shi Woo her crush.

This drama takes the audience back to the 1990s. The main character of the drama, Yu Hyechan, 29, reverts mentally to an 18-year-old girl after having a car accident. As she recovers her memory and the relationship with her husband, Kang Sang-yeong, she goes through many hilarious and heart-moving moments.
-- KBS Global Marketing