I believe most japanese people aren't really biased towards same-sex couples (they had many before opening up to the rest of the world). The minority that do though tend to be really loud and are comparatively younger.
So it's understandable that gramma is comfortable with same sex couples
You got some trouble girl… like not every freakin story has to be about finding love and a lot of old people dont care about same sex relationship. Like where are you from? Usa? XD
India
Literally in my name
most japanese aren't against gay relationship, and the fact that it's fiction also adds ont3the "it's not real life" aspect so it's more easily acceptable. i don't doubt that if someone close to her was gay, she'd react differently.
but also japanese history was very open to gay relationships, a bit like in ancient greece, with a system of mentorship with an older man taking care of a younger man and having a sexual relationship. if you see old japanese paintings with men shaving the middle of their head, it's the mentee, they let their hair grow back when they stop being mentored and become mentor instead.
so i just glanced through those chapters
i disliked the love angle for that girl, would have been better if granny found love
also why does this manga never address her shock at reading BL + her views on homosexuality? no way a 75 yr old woman just accepts it as something normal