The day Yeonu’s contract marriage came to an end was also the day that she witnessed her soon-to-be ex-husband, Seonjae, die right in front of her eyes. But when a twist of fate has her travel 100 days back in time before the tragic accident, she decides to do everything she can to stop the accident from happening. With a second chance to make things right, Yeonu is determined to make sure that, this time around, they get their happy ending.

"This time, I will make sure we have a happy ending!"