ABCD refers to South Asian Americans born and raised in the USA, in contrast to those who were born overseas and later settled in the USA.
Two spoiled young men: Johns, son of a billionaire, and his cousin Korah, whose mother left for Paris with her new husband, enjoy their luxurious life in NYC. After a disco fight, Johns's dad sends the boys to India for safety, telling them it's a vacation. But Dad blocks their credit cards, by which they must live and attend college through poverty. They tell their college mates they opted for this lifestyle to learn about their motherland. Their made up story gives them celebrity status and they become famous.