Ten years ago, Shigure divorced her husband and lost custody of her only son, living apart from him for a long time. After her husband's death, she finally reunites with her son. Though she had always wished for her son's happiness during their separation, Shigure's feelings gradually transform into an unnatural love. Meanwhile, her son, having felt the long absence of his mother, also begins to develop deeper emotions toward her. Upon reuniting, the two embark on a new relationship fueled by this forbidden desire.