Oh boy. Dr. Frene published a study titled "Chinese racial* characteristics: observations from a German psychologist".
Although it was published in 1941, you still can't access the file digitally because of copyright.
*民族性 could also mean "national".
Frene was a fan of right-wing nationalist Mitsuru Toyama as well as Nietzsche. He ended some of his letters with "Furuno Chuichi", which seems to have been his self-chosen Japanese name.
In the NDL there's a 1941 work by a 古野忠一, could it be him?