Ji Hye (Han Seung Yeon) is a cheerful girl who is straightforward about her feelings. She has a boyfriend named Hyun Woong (Yun Woo Jin), but he has never said I love you even though they have been dating for over 2 years. Ji Hye decides to break up with him, but the next day she hears that he passed away in a car accident. A year after his death, Ji Hye decides to jump from an apartment rooftop out of guilt. But when she arrives at the 7th floor, she finds herself back to the time when she was 7 years old. When she arrives on the 22nd floor, she is 22 years old, the time when she met Hyun Woong for the first time. With this newfound insight, Ji Hye decides to attempt to save Hyun Woong from his destined death.
Han Seung Yeon as Ji Hye
Yun Woo Jin as Hyun Woong
Song Jae Rim as time slip helper