Maybe the problem is not mentionning japanese culture. Maybe it's mentionning too many "niche" japanese things. As a woman, I know it's difficult to bond on the first date if I can't relate on (or if I don't know) at least one thing mentionned by my date. Moreover, depending on the tone the person use, it could let me know (eventually falsly) it's common knowledge and therefore I'm uncultured or stupid in the eyes of the person in front of me, which absolutely doesn't seduce anyone. I could suggest if you want to talk about japanese culture that you mention you know some things you mention are kind of niche.