Saori had been living alone for her gravure work but decided to quit and return to the countryside. Upon returning home, she found that her younger brother Taiichi had grown up physically but was still a shy virgin who fidgeted over obligation chocolates. Saori intended to tease this innocent Taiichi by showing off her cleavage and seducing him, but he became more aroused than expected and ended up pushing her down. From that day on, Taiichi, transformed into a sex beast, relentlessly had his way with Saori in their home with no escape…
