I’m not a native speaker, but I’ve studied Japanese for more than a decade. There are no singular, non-gendered third person pronouns, so there is no equivalent of a singular they. Although there is an equivalent of a plural they, it’s not completely gender neutral. The equivalent of him is kare, and the equivalent of her is kanojo. You can make them plural by ending “ra” on to the end of them. Kanojora is used only for groups of women/girls, and karera can be used for a group of men/boys, or a mixed-gender group. That makes the root meaning of karera male coded even if it’s used in a gender neutral manner, so non-binary people might prefer not to use that.
This shouldn’t however be a major issue for Japanese speakers, as first person pronouns are the only ones that are in frequent use. Unlike English, where you use pronouns to avoid repitition, you can completely omit them in Japanese, so instead of asking “Has Asami done her homework?” in English, you would ask “Has Asami done homework?” It’s also preferable to use names instead of 2nd/3rd person pronouns. Instead of asking “How about you?”, you’d ask “How about (person’s name)?” It’s probably much easier for a non-binary person to ask that no pronouns be used for them
When I had sex ed in the late 90's, I was shown videos with real (but obviously non-sexualized) nudity. I don't remember there being any controversy about that at all, and I went to a Christian school (Anglican).