Because of irrational fears of contamination, Japan's hibakusha — the survivors of the nuclear bombings of Hiroshima and Nagasaki — suffered discrimination. Try to imagine having an atom bomb dropped on you by a foreign enemy, then to have your own people turn against you. There is another group in Japan, ethnically and linguistically no different to any other Japanese, that would surely understand that predicament.
The dowa people (also known by terms such as burakumin) are descendants of an Edo Period (1603-1868) caste system that placed the eta and hinin people on the lowest rung of the social structure.
The eta, meaning "full of filth," were typically allocated jobs involving contact with leather, but also worked as executioners, grave and ditch diggers, slaughterhouse workers, torturers, cremation workers and sewerage cleaners.