New Underground History of Japanese Violence: Vengeance Demon (1969)

A young brother and sister live an ostracized life in rural 20th century Japan. Their family had been cast out from the village because their parents suffered from tuberculosis. And the rest of the townsfolk believed that tuberculosis was a genetic disease which gave the town a bad reputation. One day the town "leader" convinces the rest of the peasants to kill the two brothers in order to acquire their land and share it among them. The two brothers are attacked and the boy is tortured and left for dead, while the sister is raped by all the men in the village. As a result from the trauma, she loses her sanity. The boy survives the tortures and the beatings and decides to take revenge, killing all the adult inhabitants from the village. During the killings the viewer gets to realize that most of the town's inhabitants are corrupt and filled with vices, while they hypocritically spent many years accusing the two brothers of committing the acts of sin and debauchery they themselves practiced. Later the sister, in an act of desperation, commits suicide. Which further damages her brother's sanity and his decision to punish all the townsfolk and finally retire from the society which unjustly punished and hurt the two youngsters.