Jung Yeol and Na Ra fell in love with each other and got married. During their marriage, they have grown to hate each other due to their personality differences. They decide to get a divorce. A month later, their divorce will be finalized. But, on the day that they applied for a divorce, they get into a car accident. When they wake up at the hospital, they have both lost their memories and do not remember each other.
Suzuri Kanna is married to Suzuri Kakeru. After 15 years of marriage, Kakeru suddenly dies in an accident. Prior to the accident, their marriage was going through difficulties and they were on bad terms with each other. Now, Kanna is about to start her new life. At that time, she obtains a way time travel through time. She travels to the past and she meets young Kakeru, right before she met him for the first time. Seeing the younger Kakeru, she realizes that she loved him and she falls in love with him again. She decides to save him from his death that happens 15 years later.
The leads gain the chances through a third party to redo specific bits of their past. They receive the knowledge from that third party, and try to alter those specific bits of the past to end it on a happier note; at the same time altering the present they are currently in. The more of those bits they altered that built up, the more the future diverged from it's original course.
Iwase Ken and Yoshida Rei have been friends since elementary school. Ken is obstinate and unskilled in love, but he fell long ago for the lively and cheerful Rei. But Rei is about to get married to another man. While Ken and other friends from high-school attend the wedding ceremony, a fairy appears and sends Ken back in time, giving him a second chance to win the girl he loves
Housewife Miyazawa Tomomi, her husband out of a job, loses her treasured home as her family is forced to do with less during the recession. Her one ray of sunshine is her upcoming middle school class reunion, where she hopes to meet old friends as well as old flames. The class reunion, however, turns out to be more of turning point not only for her but for the others as well. At the party, she reunite with her old friends Sugiyama Kosuke, Nishikawa Yoko, Okubo Shinichi. Just how will these four people's lives change after their class reunion...
