Chou Man'in ~Joshi Seido Shanai Choukyou~

The main character is a detective, his job ranges from lover affair researches to searching for missing pet animals. His job is easy but not lucrative. One day, he receives a job offer with great pay. It seems like just a background research but not that simple. "Sex Research"...? This is a research into sex knowledge and bodies of girls. At first, he is suspicious about this offer but decides to accept it once he sees photos of beautiful girls, chosen randomly, given to him. He starts to do "Sex Research"....