Hiroki arrives at a beautiful mansion as a private tutor for a young girl named Yuki. After drinking some tea affered by Shizuka, Yuki* sister, Hiroki falls unconscious. Hiroki finds herself tied to the bed, naked. She cannot defend herself from being sexually molested by Yuki amd Shizuka, as they insert sex toys into her available orifices, and perform various sex acts. Soon, the shocking family secret is revealed. Will Hiroki be able to defend herself? What will happen to Hiroko? Experience the sexual debachery of the two sisters as they use Hiroko as their living sex toy.<br />