I know they likely were, but the mangaka really should have made a point of saying he throughly washing the intestines and offal before using it as food or ingredients for soap...
“Only I, an advanced Japanese man, could think of using all of an animal. There’s no way peasants would ever consider using different parts of an animal!”
“Only I, an advanced Japanese man, could think of using all of an animal. There’s no way peasants would ever consider using different parts of an animal!”
That's not at all certain. A single bear's ranging can be over a hundred square kilometers. Gioven that it took them rougly a day to reach it, the settlement should be well within this area.
The theme of the educated Japanese man teaching the Western looking barbarians the wonders of cilivisation is indeed quite thick in this manga. There would be many easy ways to have the isekaied person actually introduce things that didn't yet exist historically (at least widely) in a society looking like that, but the über lazy isekai authors find any research too bothersome and rather just half-ass all details.
Doesn't know how to make simple soap but divides light into the spectrum and is aware of the danger of UV radiation specifically. This author is neck deep in nonsense.