The "their" in the title also doesn't exist in the Japanese translation, and I do honestly think it missing in Japanese is a big deal in both cases.
Earlier this year, Toby spoke at length about why the game is only officially in English and Japanese
Toby Fox Defends Limited Language Options In Undertale And Deltarune: 'I Want It To Match My Vision' - Game Informer
Quoting the most relevant part:
" I know it sucks that there are no other official translations for UNDERTALE. But I want to make it clear that this isn’t because I have a grudge against other countries. It’s because, if I release something official, I want it to match my vision. I was only able to do this for the Japanese version because I know Japanese myself, and I worked very closely with our brilliant translator to thoroughly check the text. I am not against official translations for other languages if we could make it work the same way… In the past I have looked into various options with my publisher, 8-4, but nothing has come of that yet. Maybe I should try a different approach." - Toby Fox, March, 2026
Toby is fluent in Japanese, and personally oversees it.
Mostly, I just want a definitive answer on this because I hate the fighting. You can't go on twitter or reddit without them using this article as more fuel for the fire now. Hell, I've seen this very page quoted and cited as proof the community is toxic (Which is crazy, everyone here has been very civil and is just trying to do the right thing by the plot <3)
Maybe Toby will see the confusion and issue a statement, like he did with Kris, or a hotfix will simply clear up the language (by either changing the Japanese to be consistent with English, or the English to be consistent with Japanese).
Regardless, unless I get new information, I'm gonna try resist the stupid journalist in me needing to keep pushing for this. I keep hearing my editor in my head who would have chewed me out for this, but this isn't a publication, this isn't a paper, and everyone is doing their best. And I appreciate that.