My first openly gay friends were a couple, I never really payed any attention to them until one day I saw one of them sitting on the other's lap (which isn't common where I live, it is in the city where I come from though, so that is why I was suprised), then on another day I saw them kiss, then it clicked, I thought "oh, they're gay, huh, I never noticed", I went along with it, it's none of my business after all. I got to work with them on some assignments and got to know them, I became a friend of one of them because she was one of the 5 people from the entire class who didn't had to take english class, she told me a some stories of discrimination against her and her partner, one of them happened after I met them, they got banned from the library for a week due to some bullshit reason (the librarian said they were kissing, but they weren't even doing anything near that), my school was very open-arms towards LGBT, they do punish students and staff for discrimination, so they managed to solve the problem, but they spent days going from one place to another, I even went with my friend to keep her some company because the offices close early.
It gave me a new view tbh, because after that, I discovered that 3 other people on my classroom were LGBT along with some others outside of my class, I just never really payed attention to them on that aspect and thus didn't knew how they were treated sometimes, despite interacting with some every day.
I wonder how things are in Japan? I don't remember gay marriage being allowed, iirc.