"English doesn't really have any equivalent whatsoever to Japanese honorifics, so we just completely leave them out of our subtitles because there's no way that our English-speaking audience could possibly grasp their significance in explaining these character's relationship with each other"
There is a character named Robert Thomson.
At work, he's known as Robert by his coworkers and Thomson by his boss. At home, the people in his neighborhood call him Rob. His parents, spouse, and closest friends call him Robbie. His best friend from childhood calls him Robbie and also sometimes calls him Roberto. The children in his neighborhood call him Mr. Rob but when he does volunteer work at the library the kids there call him Mr. Thomson. Children in the wild who don't know him personally call him sir. When he goes to anywhere with reception, he's typically addressed as Thomson.
So explain to me again why English speaking audiences can't grasp that those kids are calling that woman Oneechan because she's a young adult woman that they aren't personally acquainted with, and more importantly why you chose to localize that to her given name and not the equivalent of "Miss" or even "Miss Given Name"? Because if your goal is to replicate the experience that the original Japanese audience would have with those characters, you're failing spectacularly. Because now not only do you have a bunch of kids going around calling adults by their given names when in the original language they're calling them a cultural equivalent to Miss or Mister, but your insistence on removing all honorifics and just using names means that there's no absolutely zero difference in the way a person is addressed by the people closest to them and total strangers. Which is not only wildly inaccurate to how the Japanese audience would experience that, it's not even that accurate to English, either.
