Do you have a source/specific episode for "material world" and "spirit world" being lowercase in either of the anime?
I remember now that they're lowercase in the novels.
The only thing I can clearly recall relating to the three worlds is the "Realm of Fairies" (also known as the Fairy/Faerie Realm) from episode 4 of the OVA. I just checked and it is capitalized in the subtitles. I don't recall if the three worlds come up in the anime at all other than that...
- I don't recall which episode, but I do recall the info booklet for the TV show mentions "spirit realm" in lowercase (the booklet is by the same team who translated the show). I tend to favour the TV show over the OVA because it's newer and has corrected previous mistakes as well (Akrohd --> Akroyd for example). -Zantam03 (Talk) 12:57, 7 November 2021 (UTC)