Copying my comment from the manga series discussion
https://mangadex.org/thread/361431/1/#post_3720730:
Seeing the fantasy world named "Ireland" I was wondering if this was a case of mistranslation. (that reminded me of a incredibly rare disease localized as "bulimia" in another manga) Ready for a probably too-long comment about this one tiny thing?
イルランデ (pronounced Irurande/auto-translated Illande)
Seen on:
https://ncode.syosetu.com/n8925cq/1/ (chapter title is "Prologue: Illande")
Google translate:
https://translate.google.com/?sl=auto&tl=en&text=イルランデ&op=translate
Extremely few search results (4,990) and appear to all be relating to this manga and/or the novel it's based on (
https://www.google.com/search?q=イルランデ) lead me to believe this is a fantasy word, and not an alternate spelling of "Ireland."
Ireland gets translated as アイルランド (Airurando)
Google translate:
https://translate.google.com/?sl=en&tl=ja&text=Ireland&op=translate
Search results for this word in Japanese returns 22,300,000 results including Wikipedia for Ireland, so this appears to be the correct word for the word "Ireland".
TL;DR: The original word (イルランデ) is entirely made up but does sound a bit like "Ireland" and is possibly meant to suggest an "Ireland-like setting." I couldn't find the raws, but assuming the title screen text present on both the Russian and English translations here were also in the raws (RU:
https://mangadex.org/chapter/1109753/11, EN:
https://mangadex.org/chapter/1109920/11) then
this should probably be translated as "Irlandes" as that's what appears in the text. Even if that isn't in the original raws, the word "Irlandes" is close enough to Ireland without actually being an actual country name, and therefore accomplishes the same thing the original fantasy word seems to in Japanese (and accomplishes this better than google translate's "Illande" does, as that fails to capture how similar the word sounds to Ireland in Japanese, lacking an R)
(note: the Russian translation appears to make the same mistake, just straight translating it as "Ireland" in the manga description and chapter title. Which makes sense, as it appears the same Russian team did both translations? I'm not sure what a good localization would be in Russian.) <-- edit: disregard this, I was mistaken