There is no real comparison here, especially later on in the war. The Nazi concentration camps were brutal places that, later on, became death camps. The Japanese in the United States were interned in relatively harsh conditions, but were not subjected to any sort of brutality of the sort that was inflicted on the people in concentration camps in Germany.
The housing in camps for Japanese Americans was substandard for families, that is certain. They were put in cramped conditions and deprived of their liberty. However, they were not forced to do slave labor. They were not subjected to medical experiments. They were not killed en masse.
The internment of Japanese Americans was a stain on America's history, but it was a very small stain compared to Germany's concentration camps. There is really no serious comparison between the two.,