Maro works as a doctor. One day, Sakimi and her husband comes to the doctor's office cause of a small pain in Sakumi's breasts. He begins to gain her trust and gives her advice about married life, with a keen interest in her sexual habits. One thing leads to another, and voila. Netorare.
A school changes its rules and drops the traditional grading system. The only way to pass now is to have sex. The more sex you have, the better your chances.