Feast of the Fallen Angels
堕天使たちの狂宴
Feast of the Fallen Angels at FMovies. Datenshi-tachi no Kyōen is an OAV (1985) where the younger sister of a family (who gets in way over their heads) ends up owing the yakuza money. Because she can't pay, she is taken by the gang members to be used as a sexual toy. Then she vows to take gruesome revenge upon her perpetrators.