After her daughter Yuna dies in a suspicious fall and her grandson Keita is left in a coma, 50-year-old Reiko Shinohara learns Yuna was bullied by other mothers, led by Saori. Driven by grief and rage, Reiko undergoes plastic surgery, adopts a boy named Riku, and infiltrates Saori’s social circle to exact revenge. She exposes scandals and uncovers that Saori’s husband, politician Shindo, framed Reiko’s ex-husband Kenji, who is now terminally ill. As Reiko begins to reconsider her path, she discovers Saori had an affair with Yuna’s husband Akihiko, reigniting her vengeance. On election day, Reiko exposes Shindo’s crimes, completes her revenge, and decides to start anew. Keita awakens, and Reiko uses her inheritance to open a group home, embracing a new life with Naruse, the surgeon who helped her.