Leona, a wife, lives a modest life with her husband Hirokazu. One day, Hirokazu's father, Michiru, suddenly comes to Tokyo from Akita. Leona wishes to become closer to her husband's father, whom she rarely sees. Michiru, who senses Leona's feelings, gradually reveals her sinister true nature. When Hirokazu is not around, Michiru starts to pick on Leona. Like a spider's web, the more Leona struggles, the harder it becomes to escape. What will become of her fate?