This is review of the Light Novel. I've not read the web novels. The author says, in the afterword, that the light novel contains 70% new material. I suspect that the negative reviews are mostly based on the web novels, where the author did not have professional help with editing. Not to mention that the web novels were translated by volunteers - who, sad to say, while enthusiastic are usually not good writers.

First of all, the LN has had a GOOD translator and the translation/edited version is much better done than most. No the writing isn't great, but it is reasonably good.

The story itself starts with what is now an almost worn out premise. Person living in Japan gets drawn into a parallel, fantasy world. BUT, the story is everything, which is where this shines. For once the author talks about the drawbacks of a true medieval world. No toilet paper, no baths, food is scarce. Bandits are a true and deadly problem. Slavery is rampant and prejudice towards those who are different is real and potentially fatal. Most surprising of all is that the author grasped that in those days, even in jail, money was useful.

Everything from the way buildings were in those times, to how clothing and supplies were purchased, and even how churches worked is reasonably accurate. (And before you ask, yes, I am a student of medieval history.)

As for the plot, for the first time we have a "harem" story where there is no harem, just children that the protagonist takes under his wing. Yes they're all cute females, but the way they are treated is different, so if you're looking for lots of bouncing breasts and sex, this series is not for you.

Given the substantial difference from the web novels, I would suggest that you not read them, but rather that you wait till the LNs are released in English. Whether or not the impressive tone of the first volume can be maintained, well, who knows? However, this first volume is giving me hope for what will come next.