A husband and wife team in New York, Dorothy and Thomas Hoobler, who have never visited Japan, have created a numer of mystery stories for young adults, based on a real Japanese character, Judge Ooka. “Ooka Tadasuke (1677-1752) was a real-life Edo magistrate renowned for his wisdom and fairness in solving difficult cases.”

But it was this bit that caught my eye. More evidence of Dumbing Down?

Publishers are funny,” Tom says. “They were not interested in The
Ghost in the Tokaido Inn, I think because they thought it would
[contain] too much information. They have a very low opinion, we’re
sorry to say, of American schoolchildren…That doesn’t help, when you
can’t publish books that have any kind of a challenge to them at all.