Read Kagakuteki ni Sonzai Shiuru Creature Musume no Kansatsu Nisshi Manga:
Kurimusubi Daisuke, a man fascinated by the complex zoology of monster girls in fiction, one day finds himself transported to a world full of them! When he encounters an arachne named Neya who needs his help, Daisuke rushes to help her–which begins his new life of meeting (and researching) the beautiful creatures around him. These monstrous ladies show him more.. that he has a lot to learn, and Daisuke never dreamed he’d be able to satisfy his passion for monster girls like this!