月下香 ～偽りの絆～

After her father's death and the resulting inheritance dispute, all that's left is debt.
This unreasonable reality is thrust upon student Narumiya Kyouko...
If things continue as they are, her happy life with her brother and her future will be lost.
At this loss, the beautiful girl Tsukishita Kaori approaches the Narumiya siblings.

Kaori seduces Shirou and makes him as her pet, and then proposes to Kyouko that she should become her business partner. The job involves running a dark website called "Gekkakou", which features their young, beautiful bodies.