Anon, I’m squinting at this ask and trying to make sense of it.

I think the best answer I can come up with to your question is:

Yes, it would be very racist to say that only Japanese people are allowed to write with or use specific themes (shipcest, age gap, teacher x student, etc) in fiction.

There are no broad themes, ideas or tropes that belong to one race or culture in the world.

Please let me know if I’m misunderstanding your question!

context link