One day, Yuuji (the hero) made an appointment with his mother. But, she didn't come with him to the hospital – she worked there, along with her sister. Yuuji went to the hospital but was unsure of his mother's location. So he went to his aunt's office to ask.

As Yuuji reached the door to his aunt's office, he heard a strange noise. Inside, he couldn't believe what he saw...

Yuuji's mother was f**king her own sister with a strap-on dildo on her hospital desk!

[From DLsite English]