Let me state something first. I'm reviewing this series not as a regular ecchi manga, but as a hentai. Because yes, this one clearly trespasses the boundary, and despite being censored, a lot of things are clearly showed.
The plot revolves around Daisuke, a man who is transported into another world (yay another isekai...), where he is finally able to accomplish his most desired dream. To be the monster girl harem king. Yes, you read this right, he goes around the world banging with all sorts of monster girls. He's also a biologist, so he takes the opportunity to analise them and try to figure out how it is scientifically possible that these creatures exist and how their body works. And I have to say that some explanations, though not being perfect, are well thought for the most part. In these first 2 volumes we are presented mainly to the arachne girls and harpies, learning the origin of arachnes (they're totally mammal, from a triplets conjoining) or how harpies can fly in this body. All of this decorated with surviving information (similar to Dr. Stone, saving the distances) and some political affairs.
The problem is that the writing is far from outstanding. Sometimes the information is not given in the appropriate way, and the character's behavior is "strange". This is one of the reasons of why I think of this manga more as a hentai, because all the girls throw themselves at the protagonist without second thoughts.
This fact brings us to the key part: the sex scenes. There are a LOT of them, without showing the penetration, but with the monster girl's naked body in all their glory. And it's important to have something in mind before reading this hentai. Remember when I said that the arachne's origin are conjoining triplets? Well, this this fact doesn't apply only to the number of legs. They have a two extra pair of breasts and double vagina. Daisuke will lay with a great amount of them (I think 5 of them), so you really have to be into this. On the other part, the harpy has a loli appearance despite being adult. Having said all this, these scenes are very fulfilling and drawn in all detail, with a good balance of what to show and what not.
Last but not least, the art is a little irregular. On the "plot" parts it really shines, but when there's action and battles the quality is clearly lower.
In conclusion, as a monster girl hentai I think it truly delivers, if we consider the story parts as an extra, to give more insight of the world. But if you are only interested in the story you'll be disappointed.
