A year after her husband's death, Masayo (Mari Akikawa) has settled into daily life living alone with her son, Hiroyuki. However, her peaceful routine is once again threatened when her brother-in-law appears, demanding, "Sister-in-law, pay me back the money." The issue of repaying a large sum her late husband once borrowed from his brother becomes a pressing burden. With no means to repay, Masayo becomes the target of her brother-in-law's advances, and is soon violently forced into sex. Witnessing the assault, Hiroyuki comforts his mother with gentle words, and Masayo finds herself surrendering emotionally to her son's kindness. As their bond deepens, she is caught between familial ties and sudden, unforeseen danger.