After her mother-in-law passed away, Mizuki decided to live with her father-in-law. Unlike her husband, who is a workaholic, she begins to open up to her father-in-law, who always cares about her, but... Behind her father-in-law's kindness, her ugly desires were swirling. She was planning to obtain Mizuki's beautiful and attractive body. Unbeknownst to her, her father-in-law's poisonous fangs are about to attack Mizuki, who exposes her defenseless side.