Shiori lived a rather uneventful life at Tashen's house. She was interested in erotic content and frequently searched for information and videos online. One day, her sister and brother-in-law suddenly returned home, and the house suddenly became lively. That evening, after the family had dinner together, Shiori secretly saw her drunken brother-in-law's penis. Although it wasn't erect, it still shocked her. From then on, Shiori's mind was filled with thoughts of her brother-in-law's penis, and eventually, she secretly sneaked into the room where her brother-in-law and sister-in-law were sleeping.