After losing her husband, Ryo began living with her daughter and son-in-law six months ago following her daughter's marriage, enjoying a peaceful life with the couple. However, everything changed after a single incident. One day, she found herself captivated by the couple's intimate moments and ended up masturbating alone. That act was discovered by her son-in-law. From that moment on, there was no turning back. As her forbidden relationship with her son-in-law deepens, so does her guilt toward her daughter. Though part of her still cares for her daughter, her body and heart have already begun walking down a different path.