On the day of the wedding, Goo Hana realizes she's heading towards a loveless marriage and runs away from the ceremony. By chance, she meets her ex-boyfriend, Nam Gawi, and time-slips back to the past. Hana does everything she can to undo the wedding in the past, but the predetermined future cannot be changed.

Amid repeated failures, as she goes back to the past and faces the same trials with Gawi, she starts to feel camaraderie and comfort, and before long, the emotions of her first love, which she had forgotten, begin to resurface!