Film noir
Film noir movies are not happy movies. In happy movies, like romance movies, people fall in love, get married, and live happy lives. In film noir movies, sad things happen. A good man with a wife might need money for their rent, and borrow the money from a criminal gang leader, because the good man has no other way of getting the money. Then the bad gang leader might force the good man to do bad things to pay back the money. Maybe the bad gang leader will threaten to hurt the good man's wife. Then the good man has to decide between protecting his wife or doing a bad crime.