Leona lives a quiet life with her husband, Hiroya. One day, her father-in-law, Michiru, suddenly arrives in the city and moves into their home. Leona secretly hopes to grow closer to Michiru, who rarely interacts with his son. Sensing her vulnerability, Michiru gradually reveals his cold, manipulative nature, beginning to make advances on Leona whenever Hiroya is away. As Leona is pushed further into a corner, she finds herself trapped with no way out. Tormented by Michiru's insidious actions, her resolve begins to crumble. What fate awaits her—one that only tightens the more she struggles to escape?