It could be because of the lack of the usual amenities: a working toilet and bathroom, access to the Internet, electricity and appliances and most importantly: the japanese baths. (can't have an isekai mc that doesn't crave the onsen)
Kinda random, but why do scanlations sometimes have repeating sentences (like on page 21)? I've seen different groups do it, but this seems like some kind of pattern.
250 km/h = 69 m/s
That's way too slow.
250m/s would be closer to bullet speed, but I doubt the damage would be anything more than a puncture hole.
Maybe a mistranslation????