Tsukasa, who runs a company with her husband, enjoys a comfortable and carefree life. One day, her father-in-law suddenly returns home, and cohabitation begins. Though the couple is bewildered by his unexpected arrival, they try their best to adjust. However, during this time, Tsukasa is accidentally seen by her father-in-law. From that moment on, their married life begins to drastically change. The shock brought by the father-in-law's actions and the impact on the couple's relationship lead to an entirely new development.