In this Mature-rated take on the popular isekai fantasy genre, a man journeys into the darkest, squishiest depths of a goblin-filled dungeon in another world! There is one place that has withstood attempts by every army to conquer it—the city-sized labyrinth known as the Deepest, Most Unknowable Dungeon. But now, after dying on Earth as a young temp worker, Jean is reborn into the world with a fascination for its most infamous dungeon. With the right training and the most carefully chosen set of lustful comrades-in-arms, he may have the chance to accomplish the impossible and become a legend in a new fantasy world!

There is one place that has withstood attempts by every army to conquer it--the city-sized labyrinth known as the Deepest, Most Unknowable Dungeon. But now, after dying on Earth as a young temp worker, Jean is reborn into the world with a fascination for its most infamous dungeon. With the right training and the most carefully chosen set of lustful comrades-in-arms, he may have the chance to accomplish the impossible and become a legend in a new fantasy world!

'" Whether they're part cat, part horse, or part spider, Daisuke has always been fascinated with the uniquely exotic beauty of monster girls. When he finds himself whisked away to a fantastic world full of all manner of demihuman life, he swiftly gets to work meeting (and analyzing!) as many as he can. There''s really only one logical thing for this stranded scientist to do: he''s going to become the creature girl harem king!! "'

Science graduate Kurimusubi Daisuke continues to study the complex zoology of monster girls in the fantasy world he now calls home. While bringing peace and developing technology to their villages, he sets his sights on a side quest: add one girl of each species he encounters to his personal harem!

"Little Blue Truck is spreading cheer by delivering Christmas trees to his animal friends. Can you help count each green tree?"--

DO IT FOR SCIENCE! When he landed in a new world full of monster-folk, science graduate Daisuke had exactly two goals: learn everything he could about them and add one of each to his own personal monster-girl harem! With a harpy at his side and the whole tribe of Arachne spider-women now among his allies, everything’s looking up for Daisuke, even in the face of hostile monsters. Unfortunately, another Earthling is out there somewhere in this new world who may have a slightly tougher time...