i refuse to believe the word simps was used, its so out of place and its pretty much a western slang, no way a japanese author used that
Please learn what localisation is about lol.
Would you prefer them all to speak ye olde English, because it is after all, an anachronistic faux-renaissance society?
If a person speaks in a youthful slang of a fictional society, the best translation is to use the current youthful slang of the modern target language.
If we want to be pedantic, since Shakespeare used the then-modern slang (and is now considered Ye Olde), it should also be translated from old to new english in an appropriate way, and we're all deprived by the fact he isn't.
What I mean to say is - W translator. Or based translator. Or lit. Or epic. You should get my point by now.