Akari works as a company president's secretary. One day, her younger brother Shinji makes a move on a yakuza woman, and Shinji and Akari are kidnapped. As punishment for what his brother did, Akari is pinned down by the yakuza. After being sexually assaulted over and over again, Akari falls into the role of a sex slave. Seeing his sister like that, Shinji becomes excited by his real sister and decides to join the yakuza and take part in the action... Betrayed even by his own brother, Akari loses hope in life...