The way I've been handling this translation, for the most part, has generally avoided indulging too much into a degree of Japanese to the point where it would alienate anyone. I don't have the luxury of inline translator's notes, and I don't want to force players to have to put down the game and start researching, so all Japanese terms that aren't widely known in the foreign-language mainstream are appropriately described in English. This is generally how most localizations tend to handle this kind of thing (at least, when they don't change things outright). But I left the honorifics in; I felt they provided a nice bit of insight into how the characters see each other, which is helpful in a cast of eight characters.
But I still don't know, while I'm translating this, whether this was the right idea. It's not like this would be the first game translation to include them, because they've been seen in things like Persona 3 and 4...although it should be noted that the majority of people I've met who've played those games said it sounds forced and awkward. Then again, most of this complaint came in regards to the English voice acting forcing those honorifics out, and this game doesn't have English voice acting. So it ideally shouldn't feel as awkward...but it could still, theoretically, contribute to the cultural lockout that I mentioned earlier.
I've eschewed all family things like onii-chan because I felt they were appropriately replaced by names (both HIkari and Takeru use onii-chan, so it's not like you can even bring in an argument about a difference in reference), and the honorific -sama on the grounds that in most cases it's accurately reproduced by Lord/Lady. But then that only feels even more inconsistent - if you remove one honorific, why not remove the rest?
It's a decision I'm still tussling with, and unfortunately if I decide to strip the translation of honorifics in the end I'll have to ask the patch team to go back and remove every instance of it on top of the usual TLC, which will definitely be asking a lot of them. That said, I would like anyone interested in this patch to know that I've definitely been putting a lot of thought into this. I hope everyone will be able to provide their support when the final version is out, regardless of the decision made.