Miyu and Shuya are high school students. They have dated for 2 years. Miyu and Shuya have a promise that no matter what, they will watch a movie together on the first day of each new month. When Miyu and Shuya are on their way to the movie theater, Shuya suddenly cancels their date. Shuya seems like he is hiding something and he acts nervous. Later, Miyu goes to the place where she is supposed to meet Shuya, but she witnesses Shuya getting into a car accident. She panics, but when she wakes up she finds herself on the morning of the accident. Miyu keeps waking up on the day when Shuya got into an accident.
Tired of the men in her life being lying, married philanderers, Koharu moves away from the city and back home. Once there, she finds her family saddled with debt and no way out. That is until a handsome stranger offers to settle the debt if Koharu agrees to marry him. And if that wasn't crazy enough, he already has two wives!
