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.
Shinichi debuted as a novelist at a young age, but his career has been stagnant for many years. He also has broken up with his girlfriend. His day have now become gloomy. At this time, Yuko and her son moves into Shinichi's home. Yuko is the ex-wife of Shinichi's friend. Shinichi lets them stay at his house. Shinichi writes his novel every night, while Yuko goes out at night to date men. She is conflicted with her feelings to act as a strong parent and to deal with her unspeakable loneliness. Yuko’s son, feeling the loss of his father's presence, begins to admire Shinichi. With their living arrangement, Shinichi and Yuko try keep their distance from each other. But one night..
